Conducting a Good Experiment I: Variables and Control

Size: px
Start display at page:

Download "Conducting a Good Experiment I: Variables and Control"

Transcription

1 CHAPTER SIX Conducting a Good Experiment I: Variables and Control 1 The Nature of Variables! Variable! A variable is an event or behavior that can assume at least two values.! Bridgman (1927) suggested that researchers should define their variables in terms of the operations needed to produce them. " Such definitions allow others to replicate your research and are called operational definitions. 2 Independent Variables! Independent Variables (IV s)! IV s are those variables that the experimenter purposely manipulates.! The IV constitutes the reason the research is being conducted; the experimenter is interested in determining what effect the IV has. 3 1

2 Types of Independent Variables! Physiological IV! The physiological state of the participant that the experimenter manipulates.! Experience IV! Manipulation of the amount or type of training or learning.! Stimulus or environmental IV! An aspect of the environment that the experimenter manipulates. 4 Participant Characteristics! Participant characteristics are aspects of the participant, such as age, sex or personality traits, that are treated as if they are IVs.! But they are not IV s because they cannot be manipulated by the experimenter. 5 Extraneous Variables (Confounders)! Extraneous variables! Uncontrolled variables that can cause unintended changes between groups.! Confounding! A situation in which the results of an experiment can be attributed to either the operation of an IV or to an extraneous variable.! When a study is confounded, there is no way to determine which variable is responsible for any observed differences.! Researchers learn from mistakes and control the extraneous variable in the next experiment. 6 2

3 Extraneous Variables (Confounders) A. Difference between two groups with no confounder operating. B. Difference between two groups when a confounder is present and has moved the groups closer together. C. Difference between two groups when a confounder is present and has moved the groups farther apart. 7 Dependent Variables! Dependent Variable (DV)! A response or behavior that is measured; the data or results of an experiment.! It is desired that any changes in the DV are directly related to the manipulation of the IV.! The literature review provides valuable guidelines as to which behavior or response should be measured.! Once the DV has been selected, method of measuring or recording it must be determined. 8 Recording or Measuring the DV! Correctness! Only the correct responses are counted.! Rate or Frequency! Rate of responding determines how rapidly responses are made during a specified time period.! The number of responses or events that occur within a specified time period is the frequency.! Degree or Amount! Latency of Duration 9 3

4 Different Rates of Responding. Recording More than One DV! If you have the measurement capabilities, there is nothing to prohibit the recording of more than one DV.! If recording an additional DV makes a meaningful contribution to your understanding of the phenomenon under study, then you should give it serious consideration. 11 Characteristics of a Good DV! A DV is valid when it measures what the experimental hypothesis says it should measure.! A good DV must be directly related to the IV and must measure the effects of the IV manipulation as the experimental hypothesis predicts it will.! A good DV is also reliable. 12 4

5 Nuisance Variables! Nuisance Variables! Unwanted variables that can cause the variability of scores within the experimental groups to increase.! Nuisance variables only increase the spread of scores within a distribution; they do not cause a distribution to change its location. 13 Nuisance Variables A. Spread of scores within a group when a nuisance variable is not operating. B. Spread of scores when a nuisance variable is operating. A. A comparison of two groups when a nuisance variable is not operating. B. A comparison of the same two groups when a nuisance variable is operating. 14 Controlling Extraneous Variables! The experimenter must exercise control over both extraneous variables and nuisance variables so the results of the experiment are as meaningful (no extraneous variables present) and clear (minimal influence of nuisance variables) as possible. 15 5

6 Basic Control Techniques! Randomization! A control technique that ensures that each participant has an equal chance of being assigned to any group in an experiment! Elimination! A control technique whereby extraneous variables are completely removed from an experiment.! Constancy! A control technique by which an extraneous variable is reduced to a single value that is experienced by all participants.! Balancing! A control procedure that achieves group equality by distributing extraneous variables equally to all groups.! Counterbalancing! A procedure for controlling order effects by presenting different treatment sequences. 16 Counterbalancing! Within-Subject counterbalancing! Presentation of different treatment sequences to the same participant. 17 Counterbalancing! Within-Group counterbalancing! Presentation of different treatment sequences to different participants. " Three basic requirements: " Each treatment must be presented to each participant an equal number of times. " Each treatment must occur an equal number of times at each testing or practice session. " Each treatment must precede and follow each of the other treatments an equal number of times. 18 6

7 Table 6-3 Within-Group Counterbalancing for the Two-Cola Challenge When Six Participants Are Tested Counterbalancing! Complete counterbalancing! All possible treatment sequences are presented.! You can calculate the number of sequences by using the formula n! (n factorial).! Incomplete counterbalancing! Only a portion of all possible sequences are presented. 20 Table 6-6 An Incomplete Counterbalancing Approach 7

8 Counterbalancing! Sequence or Order Effects! Sequence or order effects are produced by the participant s being exposed to the sequential presentation of the treatments. " The sequence or order effect depends on where in the sequential presentation of treatments the participant s performance is evaluated, not which treatment is experienced.! Carryover Effects! The effects of one treatment persist or carry over and influence responses to the next treatment. 22 8

Measures of Dispersion. Range. Variance. Standard deviation. Measures of Relationship. Range. Variance. Standard deviation.

Measures of Dispersion. Range. Variance. Standard deviation. Measures of Relationship. Range. Variance. Standard deviation. Measures of Dispersion Range Variance Standard deviation Range The numerical difference between the highest and lowest scores in a distribution It describes the overall spread between the highest and lowest

More information

04/12/2014. Research Methods in Psychology. Chapter 6: Independent Groups Designs. What is your ideas? Testing

04/12/2014. Research Methods in Psychology. Chapter 6: Independent Groups Designs. What is your ideas? Testing Research Methods in Psychology Chapter 6: Independent Groups Designs 1 Why Psychologists Conduct Experiments? What is your ideas? 2 Why Psychologists Conduct Experiments? Testing Hypotheses derived from

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 381 Exam #2 E Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) An approach to qualitative research that focuses on building theories is known

More information

Topic #4 CONTROL. 1. What are the threats to the validity of a contemplated piece of research?

Topic #4 CONTROL. 1. What are the threats to the validity of a contemplated piece of research? ARTHUR PSYC 204 (EXPERIMENTAL PSYCHOLOGY) 15A LECTURE NOTES [02/22/15] CONTROL PAGE 1 Topic #4 CONTROL Central issue is, of course, one of research validity. Key questions in research: 1. What are the

More information

Topic #4 CONTROL. 1. What are the threats to the validity of a contemplated piece of research?

Topic #4 CONTROL. 1. What are the threats to the validity of a contemplated piece of research? ARTHUR PSYC 302 (EXPERIMENTAL PSYCHOLOGY) 18C LECTURE NOTES [10/03/18] CONTROL PAGE 1 Topic #4 CONTROL Central issue is, of course, one of research validity. Key questions in research: 1. What are the

More information

CHAPTER 8 EXPERIMENTAL DESIGN

CHAPTER 8 EXPERIMENTAL DESIGN CHAPTER 8 1 EXPERIMENTAL DESIGN LEARNING OBJECTIVES 2 Define confounding variable, and describe how confounding variables are related to internal validity Describe the posttest-only design and the pretestposttest

More information

Using The Scientific method in Psychology

Using The Scientific method in Psychology CHAPTER FIVE Using The Scientific method in Psychology 1 The Scientific Method in Psychology Science The key elements of the scientific approach are: Objective measurements of the phenomenon under consideration

More information

FORM C Dr. Sanocki, PSY 3204 EXAM 1 NAME

FORM C Dr. Sanocki, PSY 3204 EXAM 1 NAME PSYCH STATS OLD EXAMS, provided for self-learning. LEARN HOW TO ANSWER the QUESTIONS; memorization of answers won t help. All answers are in the textbook or lecture. Instructors can provide some clarification

More information

Psychology Research Process

Psychology Research Process Psychology Research Process Logical Processes Induction Observation/Association/Using Correlation Trying to assess, through observation of a large group/sample, what is associated with what? Examples:

More information

Designing Experiments... Or how many times and ways can I screw that up?!?

Designing Experiments... Or how many times and ways can I screw that up?!? www.geo.uzh.ch/microsite/icacogvis/ Designing Experiments... Or how many times and ways can I screw that up?!? Amy L. Griffin AutoCarto 2012, Columbus, OH Outline When do I need to run an experiment and

More information

Chapter 9: Experiments

Chapter 9: Experiments Chapter 9: Experiments WHAT IS EXPERIMENTATION? Experiments are studies involving intervention by the researcher beyond that required for measurement. The usual intervention is to manipulate some variable

More information

Scientific Research. The Scientific Method. Scientific Explanation

Scientific Research. The Scientific Method. Scientific Explanation Scientific Research The Scientific Method Make systematic observations. Develop a testable explanation. Submit the explanation to empirical test. If explanation fails the test, then Revise the explanation

More information

PYSC 224 Introduction to Experimental Psychology

PYSC 224 Introduction to Experimental Psychology PYSC 224 Introduction to Experimental Psychology Session 8 Controlling Extraneous Variables Lecturer: Dr. Margaret Amankwah-Poku, Dept. of Psychology Contact Information: mamankwah-poku@ug.edu.gh College

More information

Chapter 13 Summary Experiments and Observational Studies

Chapter 13 Summary Experiments and Observational Studies Chapter 13 Summary Experiments and Observational Studies What have we learned? We can recognize sample surveys, observational studies, and randomized comparative experiments. o These methods collect data

More information

Experiment Design 9/17/2015. Mini summary of Green & Bavelier

Experiment Design 9/17/2015. Mini summary of Green & Bavelier Experiment Design Main Parameters Experimental design is not a linear Independent Variable planning process What will you manipulate either between subjects or within subjects? Task What will subjects

More information

Chapter 11: Experiments and Observational Studies p 318

Chapter 11: Experiments and Observational Studies p 318 Chapter 11: Experiments and Observational Studies p 318 Observation vs Experiment An observational study observes individuals and measures variables of interest but does not attempt to influence the response.

More information

2-Group Multivariate Research & Analyses

2-Group Multivariate Research & Analyses 2-Group Multivariate Research & Analyses Research Designs Research hypotheses Outcome & Research Hypotheses Outcomes & Truth Significance Tests & Effect Sizes Multivariate designs Increased effects Increased

More information

Chapter 2. The Research Process: Coming to Terms Pearson Prentice Hall, Salkind. 1

Chapter 2. The Research Process: Coming to Terms Pearson Prentice Hall, Salkind. 1 Chapter 2 The Research Process: Coming to Terms 2009 Pearson Prentice Hall, Salkind. 1 CHAPTER OBJECTIVES - STUDENTS SHOULD BE ABLE TO: Describe the research process from formulating questions to seeking

More information

Chapter 13. Experiments and Observational Studies. Copyright 2012, 2008, 2005 Pearson Education, Inc.

Chapter 13. Experiments and Observational Studies. Copyright 2012, 2008, 2005 Pearson Education, Inc. Chapter 13 Experiments and Observational Studies Copyright 2012, 2008, 2005 Pearson Education, Inc. Observational Studies In an observational study, researchers don t assign choices; they simply observe

More information

Chapter 9 Experimental Research (Reminder: Don t forget to utilize the concept maps and study questions as you study this and the other chapters.

Chapter 9 Experimental Research (Reminder: Don t forget to utilize the concept maps and study questions as you study this and the other chapters. Chapter 9 Experimental Research (Reminder: Don t forget to utilize the concept maps and study questions as you study this and the other chapters.) In this chapter we talk about what experiments are, we

More information

Villarreal Rm. 170 Handout (4.3)/(4.4) - 1 Designing Experiments I

Villarreal Rm. 170 Handout (4.3)/(4.4) - 1 Designing Experiments I Statistics and Probability B Ch. 4 Sample Surveys and Experiments Villarreal Rm. 170 Handout (4.3)/(4.4) - 1 Designing Experiments I Suppose we wanted to investigate if caffeine truly affects ones pulse

More information

The Research Process: Coming to Terms

The Research Process: Coming to Terms The Research Process: Coming to Terms Describe the research process from formulating questions to seeking and finding solutions. Describe the difference between dependent and independent variables. Identify

More information

Experimental Research. Types of Group Comparison Research. Types of Group Comparison Research. Stephen E. Brock, Ph.D.

Experimental Research. Types of Group Comparison Research. Types of Group Comparison Research. Stephen E. Brock, Ph.D. Experimental Research Stephen E. Brock, Ph.D., NCSP California State University, Sacramento 1 Types of Group Comparison Research Review Causal-comparative AKA Ex Post Facto (Latin for after the fact).

More information

Psychology Research Process

Psychology Research Process Psychology Research Process Logical Processes Induction Observation/Association/Using Correlation Trying to assess, through observation of a large group/sample, what is associated with what? Examples:

More information

VARIABLES AND MEASUREMENT

VARIABLES AND MEASUREMENT ARTHUR SYC 204 (EXERIMENTAL SYCHOLOGY) 16A LECTURE NOTES [01/29/16] VARIABLES AND MEASUREMENT AGE 1 Topic #3 VARIABLES AND MEASUREMENT VARIABLES Some definitions of variables include the following: 1.

More information

Chapter 2. The Data Analysis Process and Collecting Data Sensibly. Copyright 2005 Brooks/Cole, a division of Thomson Learning, Inc.

Chapter 2. The Data Analysis Process and Collecting Data Sensibly. Copyright 2005 Brooks/Cole, a division of Thomson Learning, Inc. Chapter 2 The Data Analysis Process and Collecting Data Sensibly Important Terms Variable A variable is any characteristic whose value may change from one individual to another Examples: Brand of television

More information

Chapter 1: Review of Basic Concepts

Chapter 1: Review of Basic Concepts Chapter 1: Review of Basic Concepts Multiple Choice 1. A researcher uses a six-sided dice to determine group membership. The sampling method being used is: a. random sample. b. stratified sample. c. convenience

More information

Research Methods in Psychology UNIT 3 PSYCHOLOGY 2013

Research Methods in Psychology UNIT 3 PSYCHOLOGY 2013 + Research Methods in Psychology UNIT 3 PSYCHOLOGY 2013 + Chapter 1 Summary 2 Experimental research: construction of research hypotheses; identification of operational independent and dependent variables

More information

Topic #6. Quasi-experimental designs are research studies in which participants are selected for different conditions from pre-existing groups.

Topic #6. Quasi-experimental designs are research studies in which participants are selected for different conditions from pre-existing groups. ARTHUR PSYC 204 (EXPERIMENTAL PSYCHOLOGY) 17A LECTURE NOTES [03/08/17] QUASI-EXPERIMENTAL DESIGNS PAGE 1 Topic #6 QUASI-EXPERIMENTAL DESIGNS Again, central issue is one of research validity. Quasi-experimental

More information

Chapter 8: Estimating with Confidence

Chapter 8: Estimating with Confidence Chapter 8: Estimating with Confidence Key Vocabulary: point estimator point estimate confidence interval margin of error interval confidence level random normal independent four step process level C confidence

More information

Research Methods & Design Outline. Types of research design How to choose a research design Issues in research design

Research Methods & Design Outline. Types of research design How to choose a research design Issues in research design Research Methods & Design Outline Types of research design How to choose a research design Issues in research design Types of Research Design Correlational Field (survey) Experimental Qualitative Meta-analysis

More information

Educational Psychology

Educational Psychology What are the Goals of Scientific Study? Unit 1 Scientific Study of Educational Psychology Prediction makes the theory Testable Describe Understand Predict Control That s just a theory. Give me the facts!

More information

Clever Hans the horse could do simple math and spell out the answers to simple questions. He wasn t always correct, but he was most of the time.

Clever Hans the horse could do simple math and spell out the answers to simple questions. He wasn t always correct, but he was most of the time. Clever Hans the horse could do simple math and spell out the answers to simple questions. He wasn t always correct, but he was most of the time. While a team of scientists, veterinarians, zoologists and

More information

Designing Psychology Experiments: Data Analysis and Presentation

Designing Psychology Experiments: Data Analysis and Presentation Data Analysis and Presentation Review of Chapter 4: Designing Experiments Develop Hypothesis (or Hypotheses) from Theory Independent Variable(s) and Dependent Variable(s) Operational Definitions of each

More information

Chapter 2 Methodology: How Social Psychologists Do Research

Chapter 2 Methodology: How Social Psychologists Do Research Chapter 2 Methodology: How Social Psychologists Do Research Methodology Social Psychology: An Empirical Science Empirical research allows us to test the validity of personal observations and folk wisdom.

More information

Research in the Social Sciences. Saturday, February 3, 18

Research in the Social Sciences. Saturday, February 3, 18 Research in the Social Sciences All sciences (including social sciences) rely on empirical evidence (information we can verify with our senses Write this Down Common Sense vs. Evidence Poor people are

More information

Wissenschftlichen Arbeiten. Research methods (II) Zhuanghua Shi

Wissenschftlichen Arbeiten. Research methods (II) Zhuanghua Shi Wissenschftlichen Arbeiten Research methods (II) Zhuanghua Shi!1 Last week Descriptive method case studies, survey, developmental study, follow-up study, documentary analysis, correlation analysis Experimental

More information

Experimental Research in HCI. Alma Leora Culén University of Oslo, Department of Informatics, Design

Experimental Research in HCI. Alma Leora Culén University of Oslo, Department of Informatics, Design Experimental Research in HCI Alma Leora Culén University of Oslo, Department of Informatics, Design almira@ifi.uio.no INF2260/4060 1 Oslo, 15/09/16 Review Method Methodology Research methods are simply

More information

Underlying Theory & Basic Issues

Underlying Theory & Basic Issues Underlying Theory & Basic Issues Dewayne E Perry ENS 623 Perry@ece.utexas.edu 1 All Too True 2 Validity In software engineering, we worry about various issues: E-Type systems: Usefulness is it doing what

More information

26:010:557 / 26:620:557 Social Science Research Methods

26:010:557 / 26:620:557 Social Science Research Methods 26:010:557 / 26:620:557 Social Science Research Methods Dr. Peter R. Gillett Associate Professor Department of Accounting & Information Systems Rutgers Business School Newark & New Brunswick 1 Overview

More information

The essential focus of an experiment is to show that variance can be produced in a DV by manipulation of an IV.

The essential focus of an experiment is to show that variance can be produced in a DV by manipulation of an IV. EXPERIMENTAL DESIGNS I: Between-Groups Designs There are many experimental designs. We begin this week with the most basic, where there is a single IV and where participants are divided into two or more

More information

SINGLE-CASE RESEARCH. Relevant History. Relevant History 1/9/2018

SINGLE-CASE RESEARCH. Relevant History. Relevant History 1/9/2018 SINGLE-CASE RESEARCH And Small N Designs Relevant History In last half of nineteenth century, researchers more often looked at individual behavior (idiographic approach) Founders of psychological research

More information

RNA-seq. Design of experiments

RNA-seq. Design of experiments RNA-seq Design of experiments Experimental design Introduction An experiment is a process or study that results in the collection of data. Statistical experiments are conducted in situations in which researchers

More information

PSYCHOLOGY Vol. II - Experimentation in Psychology-Rationale, Concepts and Issues - Siu L. Chow

PSYCHOLOGY Vol. II - Experimentation in Psychology-Rationale, Concepts and Issues - Siu L. Chow EXPERIMENTATION IN PSYCHOLOGY RATIONALE, CONCEPTS, AND ISSUES Siu L. Chow Department of Psychology, University of Regina, Canada Keywords: conditional syllogism, control, criterion of falsification, experiment,

More information

Chapter 11 Nonexperimental Quantitative Research Steps in Nonexperimental Research

Chapter 11 Nonexperimental Quantitative Research Steps in Nonexperimental Research Chapter 11 Nonexperimental Quantitative Research (Reminder: Don t forget to utilize the concept maps and study questions as you study this and the other chapters.) Nonexperimental research is needed because

More information

Experimental and Quasi-Experimental designs

Experimental and Quasi-Experimental designs External Validity Internal Validity NSG 687 Experimental and Quasi-Experimental designs True experimental designs are characterized by three "criteria for causality." These are: 1) The cause (independent

More information

Experimental and quasi-experimental designs:

Experimental and quasi-experimental designs: C82MST: Practical and statistical methods Experimental and quasi-experimental designs: Establishing causal effects of independent variables Tobias Bast School of Psychology, University of Nottingham Feynman

More information

Single-Factor, Dependent-Groups Designs

Single-Factor, Dependent-Groups Designs CHAPTER 8 Single-Factor, Dependent-Groups Designs PROLOGUE Types of Dependent-Groups Designs Within-Subjects Designs Matched-Subjects Designs Order Effects and Control Methods What Are Order Effects? Control

More information

PSY 250. Experimental Design: The Basic Building Blocks. Simple between subjects design. The Two-Group Design 7/25/2015. Experimental design

PSY 250. Experimental Design: The Basic Building Blocks. Simple between subjects design. The Two-Group Design 7/25/2015. Experimental design Experimental Design: The Basic Building Blocks PSY 250 Experimental design The general plan for selecting participants, assigning participants to experimental conditions, controlling extraneous variables,

More information

Introduction to Statistics and Research Design. Arlo Clark-Foos

Introduction to Statistics and Research Design. Arlo Clark-Foos Introduction to Statistics and Research Design Arlo Clark-Foos Dr. John Snow and Cholera 1854.London Two Branches of Statistics Descriptive Statistics Organize, summarize, & communicate Reduce large amounts

More information

Chapter 8 Experimental Design

Chapter 8 Experimental Design Chapter 8 Experimental Design Causality Review Remember from Chapter 4 that in order to make a causal inference, you need to satisfy three requirements: 1. Covariation 2. Temporal order 3. Eliminate alternative

More information

Chapter 1. Understanding Social Behavior

Chapter 1. Understanding Social Behavior Chapter 1 Understanding Social Behavior Social psychology is the scientific study of how individuals think and feel about, interact with, and influence each other individually and in groups. Model for

More information

Chapter 13. Experiments and Observational Studies

Chapter 13. Experiments and Observational Studies Chapter 13 Experiments and Observational Studies 1 /36 Homework Read Chpt 13 Do p312 1, 7, 9, 11, 17, 20, 25, 27, 29, 33, 40, 41 2 /36 Observational Studies In an observational study, researchers do not

More information

Chapter 5: Research Language. Published Examples of Research Concepts

Chapter 5: Research Language. Published Examples of Research Concepts Chapter 5: Research Language Published Examples of Research Concepts Contents Constructs, Types of Variables, Types of Hypotheses Note Taking and Learning References Constructs, Types of Variables, Types

More information

Design of Experiments & Introduction to Research

Design of Experiments & Introduction to Research Design of Experiments & Introduction to Research 1 Design of Experiments Introduction to Research Definition and Purpose Scientific Method Research Project Paradigm Structure of a Research Project Types

More information

SOCI 323 Social Psychology

SOCI 323 Social Psychology SOCI 323 Social Psychology Session 3 Doing Research In Social Psychology- Part Two Lecturer: Dr. Peace Mamle Tetteh, Department of Sociology Contact Information: ptetteh@ug.edu.gh College of Education

More information

Causal Research Design- Experimentation

Causal Research Design- Experimentation In a social science (such as marketing) it is very important to understand that effects (e.g., consumers responding favorably to a new buzz marketing campaign) are caused by multiple variables. The relationships

More information

Lesson 3 Experimental Design and Control of Variables

Lesson 3 Experimental Design and Control of Variables Lesson 3 Experimental Design and Control of Variables Learning Objectives Identify and distinguish between the different types of experimental design. Identify strengths and weaknesses of each experimental

More information

Limitations of 2-cond Designs

Limitations of 2-cond Designs Design Conditions & Variables Limitations of 2-group designs Kinds of Treatment & Control conditions Kinds of Causal Hypotheses Explicating Design Variables Kinds of IVs Identifying potential confounds

More information

Psy201 Module 3 Study and Assignment Guide. Using Excel to Calculate Descriptive and Inferential Statistics

Psy201 Module 3 Study and Assignment Guide. Using Excel to Calculate Descriptive and Inferential Statistics Psy201 Module 3 Study and Assignment Guide Using Excel to Calculate Descriptive and Inferential Statistics What is Excel? Excel is a spreadsheet program that allows one to enter numerical values or data

More information

PYSC 224 Introduction to Experimental Psychology

PYSC 224 Introduction to Experimental Psychology PYSC 224 Introduction to Experimental Psychology Session 3 Nature of scientific methodology Lecturer:, Dept. of Psychology Contact Information: mamankwah-poku@ug.edu.gh College of Education School of Continuing

More information

HPS301 Exam Notes- Contents

HPS301 Exam Notes- Contents HPS301 Exam Notes- Contents Week 1 Research Design: What characterises different approaches 1 Experimental Design 1 Key Features 1 Criteria for establishing causality 2 Validity Internal Validity 2 Threats

More information

The Research Enterprise in Psychology Chapter 2

The Research Enterprise in Psychology Chapter 2 The Research Enterprise in Psychology Chapter 2 This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including

More information

ANS: c Objective=2.2: Recognize new words and phrases that form the basis for much of the communication in research, Topic=The Language of Research

ANS: c Objective=2.2: Recognize new words and phrases that form the basis for much of the communication in research, Topic=The Language of Research Salkind_9e_TB_ch02 Key: Answer, Type, Learning Objective, Level Type A=Applied C=Conceptual F=Factual Level (1)=Easy; (2)=Moderate; (3)=Difficult LO=Learning Objective Multiple Choice Single Select M/C

More information

Vocabulary. Bias. Blinding. Block. Cluster sample

Vocabulary. Bias. Blinding. Block. Cluster sample Bias Blinding Block Census Cluster sample Confounding Control group Convenience sample Designs Experiment Experimental units Factor Level Any systematic failure of a sampling method to represent its population

More information

Introduction to Experiment Design

Introduction to Experiment Design Performance Evaluation: Introduction to Experiment Design Hongwei Zhang http://www.cs.wayne.edu/~hzhang The first ninety percent of the task takes ten percent of the time, and the last ten percent takes

More information

lab exam lab exam Experimental Design Experimental Design when: Nov 27 - Dec 1 format: length = 1 hour each lab section divided in two

lab exam lab exam Experimental Design Experimental Design when: Nov 27 - Dec 1 format: length = 1 hour each lab section divided in two lab exam when: Nov 27 - Dec 1 length = 1 hour each lab section divided in two register for the exam in your section so there is a computer reserved for you If you write in the 1st hour, you can t leave

More information

EXPERIMENTAL METHODS IN PSYCHOLINGUISTIC RESEARCH SUMMER SEMESTER 2015

EXPERIMENTAL METHODS IN PSYCHOLINGUISTIC RESEARCH SUMMER SEMESTER 2015 EXPERIMENTAL METHODS IN PSYCHOLINGUISTIC RESEARCH SUMMER SEMESTER 2015 RESEARCH CYCLE Course content WHAT IS AN EXPERIMENT? A systematic research study in which the researcher: 1) directly varies (manipulates)

More information

Research Landscape. Qualitative = Constructivist approach. Quantitative = Positivist/post-positivist approach Mixed methods = Pragmatist approach

Research Landscape. Qualitative = Constructivist approach. Quantitative = Positivist/post-positivist approach Mixed methods = Pragmatist approach Empirical Methods Research Landscape Qualitative = Constructivist approach Build theory from data Quantitative = Positivist/post-positivist approach Mixed methods = Pragmatist approach Experimental Analysis

More information

Overview of Clinical Study Design Laura Lee Johnson, Ph.D. Statistician National Center for Complementary and Alternative Medicine US National

Overview of Clinical Study Design Laura Lee Johnson, Ph.D. Statistician National Center for Complementary and Alternative Medicine US National Overview of Clinical Study Design Laura Lee Johnson, Ph.D. Statistician National Center for Complementary and Alternative Medicine US National Institutes of Health 2012 How Many Taken a similar course

More information

Objectives. Quantifying the quality of hypothesis tests. Type I and II errors. Power of a test. Cautions about significance tests

Objectives. Quantifying the quality of hypothesis tests. Type I and II errors. Power of a test. Cautions about significance tests Objectives Quantifying the quality of hypothesis tests Type I and II errors Power of a test Cautions about significance tests Designing Experiments based on power Evaluating a testing procedure The testing

More information

Student Lecture Guide YOLO Learning Solutions

Student Lecture Guide YOLO Learning Solutions Student Lecture Guide Social psychology is the scientific study of how individuals think and feel about, interact with, and influence each other individually and in groups Model for social behavior that

More information

Experimental Design (7)

Experimental Design (7) Experimental Design (7) Kerry Kilborn Department of Psychology Overview Confounding variables Experiment vs. Correlational Study Between-Subjects Design Equivalent Groups Quasi-Experiments Summary Experimental

More information

Chapter 11. Experimental Design: One-Way Independent Samples Design

Chapter 11. Experimental Design: One-Way Independent Samples Design 11-1 Chapter 11. Experimental Design: One-Way Independent Samples Design Advantages and Limitations Comparing Two Groups Comparing t Test to ANOVA Independent Samples t Test Independent Samples ANOVA Comparing

More information

2 Critical thinking guidelines

2 Critical thinking guidelines What makes psychological research scientific? Precision How psychologists do research? Skepticism Reliance on empirical evidence Willingness to make risky predictions Openness Precision Begin with a Theory

More information

Chapter 2 Multiple Choice Questions (The answers are provided after the last question.) 1. Which research paradigm is based on the pragmatic view of reality? a. quantitative research b. qualitative research

More information

RESEARCH METHODS. Winfred, research methods, ; rv ; rv

RESEARCH METHODS. Winfred, research methods, ; rv ; rv RESEARCH METHODS 1 Research Methods means of discovering truth 2 Research Methods means of discovering truth what is truth? 3 Research Methods means of discovering truth what is truth? Riveda Sandhyavandanam

More information

LEARNING. Learning. Type of Learning Experiences Related Factors

LEARNING. Learning. Type of Learning Experiences Related Factors LEARNING DEFINITION: Learning can be defined as any relatively permanent change in behavior or modification in behavior or behavior potentials that occur as a result of practice or experience. According

More information

9 research designs likely for PSYC 2100

9 research designs likely for PSYC 2100 9 research designs likely for PSYC 2100 1) 1 factor, 2 levels, 1 group (one group gets both treatment levels) related samples t-test (compare means of 2 levels only) 2) 1 factor, 2 levels, 2 groups (one

More information

THE RESEARCH ENTERPRISE IN PSYCHOLOGY

THE RESEARCH ENTERPRISE IN PSYCHOLOGY THE RESEARCH ENTERPRISE IN PSYCHOLOGY Chapter 2 Mr. Reinhard Winston Churchill High School Adapted from: Psychology: Themes and Variations by Wayne Weiten, 9 th edition Looking for laws Psychologists share

More information

In this chapter we discuss validity issues for quantitative research and for qualitative research.

In this chapter we discuss validity issues for quantitative research and for qualitative research. Chapter 8 Validity of Research Results (Reminder: Don t forget to utilize the concept maps and study questions as you study this and the other chapters.) In this chapter we discuss validity issues for

More information

CAUTIONS ABOUT THE PRACTICE EXAM

CAUTIONS ABOUT THE PRACTICE EXAM Dr. Michael Passer Psych 209, U. of Washington CAUTIONS ABOUT THE PRACTICE EXAM DEAR STUDENT: This practice tests consists of questions from past exams. By taking this practice test, you should gain an

More information

RESEARCH METHODS. Winfred, research methods,

RESEARCH METHODS. Winfred, research methods, RESEARCH METHODS Winfred, research methods, 04-23-10 1 Research Methods means of discovering truth Winfred, research methods, 04-23-10 2 Research Methods means of discovering truth what is truth? Winfred,

More information

Variable Data univariate data set bivariate data set multivariate data set categorical qualitative numerical quantitative

Variable Data univariate data set bivariate data set multivariate data set categorical qualitative numerical quantitative The Data Analysis Process and Collecting Data Sensibly Important Terms Variable A variable is any characteristic whose value may change from one individual to another Examples: Brand of television Height

More information

UNIT 1: Fundamentals of research design and variables

UNIT 1: Fundamentals of research design and variables UNIT 1: Fundamentals of research design and s Reading Assignment: Aron Reading on website: Logic & Language of Psychology Research 1. What are the goals of science and how do the types of statistics relate

More information

EXPERIMENTAL DESIGN Page 1 of 11. relationships between certain events in the environment and the occurrence of particular

EXPERIMENTAL DESIGN Page 1 of 11. relationships between certain events in the environment and the occurrence of particular EXPERIMENTAL DESIGN Page 1 of 11 I. Introduction to Experimentation 1. The experiment is the primary means by which we are able to establish cause-effect relationships between certain events in the environment

More information

EXPERIMENTAL RESEARCH DESIGNS

EXPERIMENTAL RESEARCH DESIGNS ARTHUR PSYC 204 (EXPERIMENTAL PSYCHOLOGY) 14A LECTURE NOTES [02/28/14] EXPERIMENTAL RESEARCH DESIGNS PAGE 1 Topic #5 EXPERIMENTAL RESEARCH DESIGNS As a strict technical definition, an experiment is a study

More information

Lecture 21. RNA-seq: Advanced analysis

Lecture 21. RNA-seq: Advanced analysis Lecture 21 RNA-seq: Advanced analysis Experimental design Introduction An experiment is a process or study that results in the collection of data. Statistical experiments are conducted in situations in

More information

Chapter 1: Explaining Behavior

Chapter 1: Explaining Behavior Chapter 1: Explaining Behavior GOAL OF SCIENCE is to generate explanations for various puzzling natural phenomenon. - Generate general laws of behavior (psychology) RESEARCH: principle method for acquiring

More information

Educational Research. S.Shafiee. Expert PDF Trial

Educational Research. S.Shafiee. Expert PDF Trial Educational Research: Experimental Studies Educational Research S.Shafiee Research... The systematic application of a family of methods employed to provide trustworthy information about problems an ongoing

More information

Lecture 4: Research Approaches

Lecture 4: Research Approaches Lecture 4: Research Approaches Lecture Objectives Theories in research Research design approaches ú Experimental vs. non-experimental ú Cross-sectional and longitudinal ú Descriptive approaches How to

More information

Collecting Data Example: Does aspirin prevent heart attacks?

Collecting Data Example: Does aspirin prevent heart attacks? Collecting Data In an experiment, the researcher controls or manipulates the environment of the individuals. The intent of most experiments is to study the effect of changes in the explanatory variable

More information

Chapter 4: Defining and Measuring Variables

Chapter 4: Defining and Measuring Variables Chapter 4: Defining and Measuring Variables A. LEARNING OUTCOMES. After studying this chapter students should be able to: Distinguish between qualitative and quantitative, discrete and continuous, and

More information

Empirical Research Methods for Human-Computer Interaction. I. Scott MacKenzie Steven J. Castellucci

Empirical Research Methods for Human-Computer Interaction. I. Scott MacKenzie Steven J. Castellucci Empirical Research Methods for Human-Computer Interaction I. Scott MacKenzie Steven J. Castellucci 1 Topics The what, why, and how of empirical research Group participation in a real experiment Observations

More information

Treatment Effects: Experimental Artifacts and Their Impact

Treatment Effects: Experimental Artifacts and Their Impact 6 Treatment Effects: Experimental Artifacts and Their Impact This chapter presents a substantive discussion of the evaluation of experiments and interventions. The next chapter (Chapter 7) will present

More information

Inferential Statistics

Inferential Statistics Inferential Statistics and t - tests ScWk 242 Session 9 Slides Inferential Statistics Ø Inferential statistics are used to test hypotheses about the relationship between the independent and the dependent

More information

investigate. educate. inform.

investigate. educate. inform. investigate. educate. inform. Research Design What drives your research design? The battle between Qualitative and Quantitative is over Think before you leap What SHOULD drive your research design. Advanced

More information

Validity and Quantitative Research. What is Validity? What is Validity Cont. RCS /16/04

Validity and Quantitative Research. What is Validity? What is Validity Cont. RCS /16/04 Validity and Quantitative Research RCS 6740 6/16/04 What is Validity? Valid Definition (Dictionary.com): Well grounded; just: a valid objection. Producing the desired results; efficacious: valid methods.

More information