The Scientific Approach: A Search for Laws Basic assumption of science: Events are governed by some lawful order. Goals of psychology: Measure and

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2 The Scientific Approach: A Search for Laws Basic assumption of science: Events are governed by some lawful order. Goals of psychology: Measure and describe Understand and predict Apply and control Explain and influence..of what? BEHAVIOR, THOUGHTS & FEELINGS

3 -Tentative statement about the relationship between two or more variables. - Operational Definition describes the actions or operations that will be used to measure or control each variable. Example: Experiment with the moon. Hypothesis: People act crazy during a full moon. You would have to define crazy

4 A system of interrelated ideas used to explain a set of observations. Theories must be testable. Theory construction is a gradual, iteractive process that is ALWAYS subject to revision and change. Examples of famous theories: Developmental, cognitive, behavioral, psychoanalytical, humanistic, biomedical, social

5 1. Formulate a hypothesis- 2. Design the study 3. Collect the data 4. Analyze and draw conclusions 5. Report the findings & determine your theory

6 Experiment- A research method in which the investigator manipulates a variable under carefully controlled conditions and observes whether any changes occur in a second variable as a result.

7 A condition or event that an experimenter varies or manipulates in order to see its impact on another variable. Example: Students behavior is different around their parents than at school. IV= Surroundings DV=Behavior

8 The variable that is thought to be affected by manipulation of the independent variable. Usually a measurement of some aspect of the participant s behavior. Juniors have the highest GPA at SHS. IV=Grade level DV=GPA Called dependent because depends on the manipulations of the independent variable. Also referred to as the variable being measured

9 Experimental Group- consists of the subjects who receive some special treatment in regard to the independent variable. Ex. Students who received the Charlie Notes (Printed notes) Control Group- consists of similar subjects who DO NOT receive the special treatment given to the experimental group. Ex. Students who did not receive Charlie Notes (Printed Notes) Hypothesis: Students who receive Charlie Notes perform better on the unit test than students who do not. IV: Notes DV: Score on test

10 Confounding variables: When 2 variables are linked together in a way that makes it difficult to sort out their specific effects. Extraneous variables: other than the independent variable, a variable that seems to be effecting the dependant variable. A researcher cannot tell which is having what effect on the dependent variable. Ex. Students who were in 1st period were in the control group that did not receive Charlie Notes (IV). Students in 2nd period were in the experimental group that received the Charlie Notes. What variables are confounding or extraneous?

11 Examples of confounding or extraneous variables Time of day Food intake Intelligence levels Gender Distractions Emotional issues Sleep the night before Grade levels

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13 Naturalistic Observation Observing without interfering Example: children s spontaneous acts of aggression during recess are observed and recorded. Advantages: Can be good place to start when little is known about the behavior. Can get a base line. Disadvantages: Very subjective

14 Investigation of individual subject. Advantages: can provide compelling illustrations to support a theory Disadvantages: Makes it easy to see what one expects to see based on one s theoretical slant. (Usually used to victims of suicide, these studies are called psychological autopsies.)

15 Questionnaires and interviews to gather information. Advantages: Relatively easy to collect data from large samples Disadvantages: Self-Report data often unreliable due to deception, social desirability bias, memory lapses, wishful thinking, and response sets. Example: Asking students if they ever have been drunk.

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17 Used to organize and summarize data (mean, median, mode)

18 Three Measures of Central Tendency Mean: the arithmetic average of the scores in a distribution Median: the score that falls exactly in the center of a distribution of scores. Mode: the most frequent score in a distribution Ex. 12,15,82,96,12,36,17,45,17,12,10 Mean: Median: 17 Mode: 12

19 How much the scores in data set vary from each other. When variability is great, standard Deviation will be relatively large. (and vice versa) Estimates in variability play a crucial role when researchers use statistics to decide whether the results of their studies support their hypothesis.

20 An index of the amount of variability in the data Shares direct relationship with variability. (When standard deviation increases, variation increases)

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22 Exists when two variables are related to each other. = Strong Correlation =Weak Correlation Popular examples: Students with less than 5 absences have significantly higher grades. What are the IV, DV, Confounding variables? = No Correlation

23 Correlation Coefficient

24 Used to interpret data and draw conclusions. Used by researchers to evaluate the possibility that their results might be due to the fluctuations of chance. Helps determine whether their data supports their hypothesis

25 Said to exist when the probability that the observed findings are due to chance is very low. Statistically significant findings are research results that are unlikely to be due to chance. ( Very low is considered as less than 5 chances in 100, which is referred to as the 0.05 level of significance.)

26 Repetition of a study to see if results are duplicated. Helps science identify purge erroneous findings. However, the replication process sometimes leads to contradictory results.

27 Sample- a random collection of subjects selected for observation in an empirical study Population- the much larger collection of animals or people (where the sample is drawn) that the researchers want to generalize about (A Sampling Bias exists when a sample is not representative of the population from which it is drawn.)

28 Occur when participants expectations lead them to experience some change even though they receive fake and ineffective treatment. Many physicians tell of patients being cured by prescriptions of sugar pills. Researchers guard against placebo effects whenever patients are likely to have expectations that a treatment will affect them in a certain way. Band-aids are the world largest money making placebo.

29 A tendency to give socially approved answers to questions asked about yourself. Subjects who are influenced by this bias work overtime trying to create a favorable impression. also Response Set - a tendency to respond to questions in a particular way that is unrelated to the content of the question. Example: When people say that they donated to a charity or voted in the last election (which are both impossible to determine).

30 Occurs when a researcher s expectations or preferences about the outcome of a study influence the results obtained. They see what they want to see. Create Double-Blind Studies -in which neither subjects nor experimenters know which subjects are in the experimental and control groups. Used to avoid a self fulfilling prophecy. Example: If we did an experiment using Charlie Notes the teacher nor the students would not know they were being studied.

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32 Made with help from Danielle Bruinenberg