Psychology - MR. CALLAWAY Mundy s Mill High School Unit RESEARCH METHODS

Transcription

1 Psychology - MR. CALLAWAY Mundy s Mill High School Unit RESEARCH METHODS

2 Intro to Research How do psychologists ask & answer questions? Differentiate types of research with regard to purpose, strengths, & weaknesses Why use each of the research methods? Describe how research design drives the reasonable conclusions that can be drawn How can each research method best drive the conclusions based on their results?

3 The Scientific Method 1. Observe some aspect of the universe. Formulate a question. 2. Invent a theory (hypothesis) that is consistent with what you have observed. 3. Use the theory to make predictions. 4. Test those predictions by experiments or further observations. 5. Modify the theory in the light of your results. 6. Go to step 3, if necessary. 7. Draw conclusions. 8. Report your results.

4 Hypothesis: A tentative theory that has not yet been tested. Has operational definitions: how you will measure it. (can vary among participants) The theory must be replicable. Theory aims to explain a phenomenon, not prove hypothesis. It can only support or disprove. Proving a hypothesis is impossible!

5 A theory is a system of interrelated ideas used to explain a set of observations. A scientific theory must be testable. Findings support the hypotheses: Confidence in the theory that the hypotheses were derived from grows. Findings fail to support the hypotheses: Confidence in the theory diminishes. The theory may then be revised or discarded. Theory construction: Gradual, iterative process that is always subject to revision.

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7 Types of Research 1. Descriptive 2. Correlational 3. Experimental

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9 Types of Descriptive Research 1. The Case Study 2. The Survey 3. Naturalistic Observation

10 Descriptive Research What is going on in this picture? Thus we have.. We cannot say exactly, but we can describe what we see.

11 Descriptive Research What is going on in this picture? Thus we have.. This picture of Usain Bolt hanging out with kids in the Czech Republic?

12 Who is Usain Bolt? Arguably the most naturally gifted athlete the world has ever seen, Usain St Leo Bolt, confirmed his tremendous talents when he realized his dreams by winning a phenomenal 3 gold medals & breaking three world records at the 2008 Olympic Games in Beijing, China. Bolt became the first man in Olympic history to win both the 100m and 200m races in world record times and then as part of the 4x100m team that also smashed the world record later in the meet. He created history again and became a legend at the 2012 Olympic Games in London by defending all 3 Olympic titles with 100m, 200m and 4x100m victories, the latter in a new world record time of secs. (from UsainBolt.com)

13 Descriptive Research Any research that observes & records. Does not talk about relationships, it just describes. Also called "statistical research."

14 Descriptive Research: 1. The Case Study 1 person (or situation) is observed in depth. A case study is an intensive analysis or research of an individual unit (e.g., a person, group, or event) stressing developmental factors in relation to context. Nearly every aspect of the subject's life & history is analyzed to seek patterns & causes for behavior. Hope is that learning gained from studying one case can be generalized to many others. Unfortunately, case studies tend to be highly subjective and it is difficult to generalize results to a larger population.

15 Descriptive Research: 1. The Case Study Clinical psychologists use case studies to present information about a person suffering from a particular disorder. Case studies allow researchers to get the richest possible picture of what they are studying, there are limitations... Limitations: May contain evidence that a certain researcher thought to be important. Researchers may overinflate importance because it is a small sample. Unlikely to be representative of people in general. Longitudinal case study - participants could exit & it is difficult to determine cause. Participants who exit, may do so for significant reasons compared to those who do not exit the study.

16 Descriptive Research: 2. The Survey Method For ascertaining the self-reported attitudes, opinions or behaviors of people usually by questioning a representative, random sample of people. You give a survey when you want to know how people feel. Both descriptive & correlational research. Interview, mail, phone, etc. Cheap, anonymous, diverse population, & easy to get random sampling: A sampling that represents your population you want to study.

17 Descriptive Research: 2. The Survey Method Validity of data depends upon: How questions are worded. Who was surveyed? Did they represent the population? Limitations: Willingness of people to complete survey People may say what they think others want them to say. Still is a great way to gather data & look at raw numbers.

18 Survey Method: The Bad Low Response Rate People Lie or just misinterpret themselves. Wording Effects How accurate would a survey be about the frequency of diarrhea?

19 Descriptive Research: 2. The Survey Method Students often confuse the use of surveys to measure the dependent variable in an experiment with the survey method. While surveys can be used as part of the experimental method, the survey method, as described, is a kind of correlational research in which the researcher does not manipulate the independent variable.

20 Why do we sample? False Consensus Effect: Tendency to overestimate the extent to which others share our beliefs & behaviors.

21 Descriptive Research: 3. Naturalistic Observation Observing & recording behavior in natural environment. No control or interaction: Just observation. Students often confuse naturalistic observation with field experiments. What are the benefits & drawbacks of Naturalistic Observation? Both involve doing research out in the world. However, N.O. does not impact behavior of participants

22 Examples of Naturalistic Observation The goal: get a realistic & rich picture of the participants behavior. To that end, control is sacrificed. Jane Goodall s work at Gombe Stream National Park in Tanzania for 40 years is an example of N.O. By observing chimpanzee behavior she was able to attain a deeper understanding than any human had previously. However, some of very strict scientific protocol were not always used. Goodall was not a natural scientist. Her insights though did lead to an understanding that chimps have personalities, use tools, are not vegetarians, and can behave in a VERY aggressive manner. Pictured to the right: (Top) Jane Goodall at the Houston Zoo in 2012.

23 Naturalistic Observation Drawbacks: Valuable where other methods are likely to be disruptive or misleading, however if people know they are being observed, they tend to act differently than they normally would. Also, observations can be distorted if observers expect to see certain types of behaviors. Can be fixed by having a group of observers. Hawthorne Effect = Merely selecting individuals to participate can impact their behavior and performance alone. Hawthorne Works had commissioned a study to see if its workers would become more productive in higher or lower levels of light. The workers' productivity seemed to improve when changes were made and slumped when the study was concluded. It was suggested that the productivity gain occurred due to the impact of the motivational effect on the workers as a result of the interest being shown in them.

24 Experimental Research Explores cause & effect relationships. Like other sciences, experimentation forms the backbone of research in psychology. Famous experiments in Psych: Pavlov s salivating dogs Milgram s obedience study Asch s conformity experiment Experiments are the only research method that isolates cause and effect!

25 Experimental Research Explores cause & effect relationships. Eating too many bananas causes --> Constipation

26 Experimental Terminology Independent Variable - IV: Factor that is manipulated Dependent Variable - DV: Factor that is measured Extraneous Variables: Factors that affect DV, that are not IV Experimental Group: Group exposed to IV Control Group: Group not exposed to IV Placebo: Inert substance that is in place of IV in Control Group

27 Experimental Terminology Experimental Group: Group exposed to Independent Variable, receives special treatment. Control Group: Group not exposed to Independent Variable, comparison groups.

28 Experimental Terminology Valid = research measures what the researcher set out to measure; it is accurate. Reliable = research can be replicated; it is consistent. Sample = group of participants. Population = anyone or anything that could possibly be selected to be the sample. Random Selection = every member of the population has an equal chance of being selected. Random Assignment = controls for participant-relevant confounding variables. Assignment is the process of dividing participants into groups AFTER selection. Using random assignment gives participants an equal chance of being placed into any group. Stratified sampling = a process that allows a researcher to ensure that the sample represents the population on some criteria. (example, representation of different races, genders, etc.) **Psychologists see random differently than laypeople do. Random sampling is best done using a computer, a table of random numbers, or picking names from a hat.** Participant-relevant confounding variable = Using random assignment limits the effect. Participants should not be able to choose their group. Situation-relevant confounding variable = The situations into which the different groups are put must be equivalent except for differences produced by the independent variable.

29 Experimental Method Only experiments can identify cause-and-effect relationships. Experimenter bias = a special kind of situation-relevant confounding variable. Experiment bias is the unconscious tendency for researchers to treat members of the experimental and control groups differently to increase the chance of confirming their hypothesis. Can be eliminated using double-blind procedure: neither the participants nor the researcher are able to affect the outcome of the research. (have someone who is unfamiliar with the participant role to interact with the participant) Single blind = participants do not know which group they have been assigned.

30 Experimental Method Experimental Group = gets the treatment operationalized in the independent variable. Control Group = does not get the independent variable. (without the control group, one can not know whether changes in the experimental group are due to the experimental treatment or simply to any treatment at all) Hawthorne Effect = Merely selecting individuals to participate can impact their behavior and performance alone. Hawthorne Works had commissioned a study to see if its workers would become more productive in higher or lower levels of light. The workers' productivity seemed to improve when changes were made and slumped when the study was concluded. It was suggested that the productivity gain occurred due to the impact of the motivational effect on the workers as a result of the interest being shown in them. Placebo method = an inert but otherwise identical substance. Placebo effect = People exhibit psychological effects of a drug, even though it is a placebo and not an actual drug. AKA: Reactivity

31 Experiment: POPULATION: MMHS Teachers Hypothesis - Caffeine helps keep high school teachers alert & happy. Representative Sample: Male & Female Multiple Subjects Multiple Houses, Locations Random Sample: All teacher names are put into a hat and pulled 60 names. Stratified Sample: Divide the staff into categories (male/female, new/vets, different subjects taught)

32 Experiment: Experimental Group: Group A - participants drink 2 cups of regular (caffeinated) coffee every morning for a month. Hypothesis - Caffeine helps keep high school teachers alert & happy. Control Groups: Group B - Participants drink 2 cups of decaf coffee every morning for a month Group C - Participants drink hot, brown, coffee flavored water for a month Random Sample: Once a sample is obtained, researcher randomly assigns participants to control & experimental groups. How do we assign groups? After participants are gathered, hand out numbered cards in no particular order to all. Separate by number into control & experimental groups.

33 Experiment: Independent Variable: (cause) The factor manipulated by the experimenter whose effect is being studied. Type of drink: caffeinated, decaf, water Hypothesis - Caffeine helps keep high school teachers alert & happy. Dependent Variable: (effect) The factor that may change in response to independent variable. In psych, it is usually behavior or mental process. What is measured? Behavior: Alertness/Crankiness, etc. How is it measured? Questionnaire at beginning to establish a baseline & then at the end of each day for the month.

34 In our experiment, group C is getting a placebo - they think it s coffee or caffeine, but it is not. This is to check the true effect of the independent variable.

35 Experiment: Hypothesis - Caffeine helps keep high school teachers alert & happy. Single Blind: Teachers (participants) do not know which group (control or experimental) they have been assigned. Double Blind: Teachers (participants) nor the person gathering data know which group is the control or experimental group. Which is better, why? Double blind is better, but not always necessary. It balances out bias. Confounding Variables! They are not good. Still some caffeine in decaf coffee. - Experience with coffee prior to experiment (i.e. whether they have had coffee in the past) - Amount of sleep

36 Quasi-Experiments Studies that have the same control as experiments yet do not include the random assignment of participants. EXAMPLE: Researchers want to test hypothesis that a pregnant woman s use of drugs will cause abnormalities in her developing baby. You would need to randomly assign women who are 8 weeks pregnant to a group that would be using drugs. Could you ethically complete this experiment? A quasi-experiment would be used in a case like this where researchers would not be able to do the experiment as normal. A researcher would never be allowed to administer drugs to a pregnant woman, just to test the effects on the baby. No IRB would allow it! However, there are women who do drugs and are pregnant. If you were able to get them to join the experiment, you could then test the effects. These types of situations are what make these experiments quasi or a semblance of an experiment. It seems like an experiment, but lacks the normal controls.

37 Hindsight Bias The tendency to believe,after learning the outcome, that you knew it all along.

38 Overconfidence We tend to think we know more than we do. 82% of U.S. drivers consider themselves to be in the top 30% of their group in terms of safety 81% of new business owners felt they had an excellent chance of their businesses succeeding. When asked about the success of their peers, the answer was only 39%. (Now that's overconfidence!!!)