Writing with APA style (cont.) & Experiment Basics: Variables

1. Writing with APA style (cont.) &Experiment Basics: Variables Psych 231: Research Methods in Psychology

2. Journal Summary assignment due in labs this week • Bring your textbook (or APA style manual if you’ve got one) to lab this week (using chapter 16 on APA style) Announcements

3. Introduction • Background • Literature Review • Statement of purpose • Specific hypotheses (at least at conceptual level) Body

4. Participants • How many, where they were selected from, any special selection requirements, details about those who didn’t complete the experiment • Methods (in enough detail that the reader can replicate the study) Body

5. Design (optional) • Suggested if you have a complex experimental design, often combined with Materials section • Methods (in enough detail that the reader can replicate the study) • Participants Body

6. Apparatus/Materials • Procedure • What did each participant do? Other details, including the operational levels of your IV(s) and DV(s), counterbalancing, etc. • Methods (in enough detail that the reader can replicate the study) • Participants • Design Body

7. Results (state the results but don’t interpret them here) • Verbal statement of results • Tables and figures • These get referred to in the text, but actually get put into their own sections at the end of the manuscript • Statistical Outcomes • Means, standard deviations, t-tests, ANOVAs, correlations, etc. Body

8. Chapter 8 • These are used to supplement the text. • To make a point clearer for the reader. • Typically used for: • Patterns of results • The design • Examples of stimuli Figures and tables

9. Discussion (interpret the results) • Relationship between purpose and results • Theoretical (or methodological) contribution • Implications • Future directions (optional) Body

10. #1 Clarity - say what you want to say • Acknowledge the work of others (avoid plagiarism) • Active vs. passive voice (avoid passive) • Active: “Bock and Coey (2003) hypothesized that speakers use to much passive voice …” • Passive: “It was hypothesized by Bock and Coey (2003) that speakers use to much passive voice…” Checklist - things to watch for

11. Avoid biased language • APA guidelines: • Accurate descriptions of individuals (e.g., Asian vs. Korean) • Be sensitive to labels (e.g., “Oriental”) • Appropriate use of headings • Correct citing and references • Good grammar, spelling, etc. Checklist - things to watch for

12. What behavior you want to examine • Identified what things (variables) you think affects that behavior • You’ve got your theory. So you want to do an experiment?

13. You’ve got your theory. • Next you need to derive predictions from the theory. • These should be stated as hypotheses. • In terms of conceptual variables or constructs So you want to do an experiment?

14. You’ve got your theory. • Next you need to derive predictions from the theory. • Now you need to design the experiment. • You need to operationalize your variables in terms of how they will be: • Controlled • Manipulated • Measured • Be aware of the underlying assumptions connecting your constructs to your operational variables So you want to do an experiment?

15. Hypothesis: Eating candy with peanuts improve memory performance • How might we test this with an experiment? An example

16. Characteristics of the psychological situations • Constants: have the same value for all individuals in the situation • Variables: have potentially different values for each individual in the situation • Constants: • M&Ms are eaten • Variables: • Type of M&M: peanut vs plain • Memory performance Constants vs. Variables

17. Underlying assumptions • Conceptual vs. Operational • Conceptual variables (constructs) are abstract theoretical entities • Operational variables are defined in terms within the experiment. They are concrete so that they can be measured or manipulated Conceptual Peanut candies Memory Operational Peanut M&Ms Memory test Variables

18. Independent variables (explanatory) • Dependent variables (response) • Extraneous variables • Control variables • Random variables • Confound variables Variables

19. The variables that are manipulated by the experimenter (sometimes called factors) • Each IV must have at least two levels • Remember the point of an experiment is comparison • Combination of all the levels of all of the IVs results in the different conditions in an experiment Independent Variables

20. Factor A Condition 1 Condition 2 Factor A Cond 1 Cond 2 Cond 3 Factor B Cond 1 Cond 2 Cond 3 Factor A Cond 4 Cond 5 Cond 6 1 factor, 2 levels 1 factor, 3 levels 2 factors, 2 x 3 levels Independent Variables

21. Methods of manipulation • Straightforward manipulations • Stimulus manipulation - different conditions use different stimuli • Instructional manipulation– different groups are given different instructions • Staged manipulations • Event manipulation– manipulate characteristics of the context, setting, etc. • Subject manipulations – there are (pre-existing mostly) differences between the subjects in the different conditions (leads to a quasi-experiment) Manipulating your independent variable

22. Peanut M&Ms Plain M&Ms Bottlecaps • What about our candy experiment? 1 IV: Candy type (3 levels) Choosing your independent variable

23. The variables that are measured by the experimenter • They are “dependent” on the independent variables (if there is a relationship between the IV and DV as the hypothesis predicts). Dependent Variables

24. How to measure your your construct: • Can the participant provide self-report? • Introspection – specially trained observers of their own thought processes, method fell out of favor in early 1900’s • Rating scales – strongly agree-agree-undecided-disagree-strongly disagree • Is the dependent variable directly observable? • Choice/decision (sometimes timed) • Is the dependent variable indirectly observable? • Physiological measures (e.g. GSR, heart rate) • Behavioral measures (e.g. speed, accuracy) Choosing your dependent variable

25. Conceptual level:Memory • What about our candy experiment? • Operational level: Some kind of memory test • Memorize a list of words while eating the candy • Then 1 hour after study time, recall the list of words • Measure the accuracy of recall Choosing your dependent variable

26. Control variables • Holding things constant - Controls for excessive random variability • Number of M&Ms consumed • Time of day test taken Extraneous Variables

27. Random variables – may freely vary, to spread variability equally across all experimental conditions • Randomization • A procedures that assure that each level of an extraneous variable has an equal chance of occurring in all conditions of observation. • On average, the extraneous variable is not confounded with our manipulated variable. • What your participants ate before the • experiment Extraneous Variables

28. Can you keep them constant? • Should you make them random variables? • Two things to watch out for: • Experimenter bias (expectancy effects) • the experimenter may influence the results (intentionally and unintentionally) • E.g., Clever Hans • One solution is to keep the experimenter “blind” as to what conditions are being tested • Demand characteristics – cues that allow the participants to figure out what the experiment is about, influencing how they behave Control your extraneous variable(s)

29. Confound variables • Other variables, that haven’t been accounted for (manipulated, measured, randomized, controlled) that can impact changes in the dependent variable(s) Confound Variables

30. Read chapters 3 & 5. • Bring your textbook and/or APA Publication Manual to lab (if you’ve got one) • Don’t forget your first journal summary is due this week in lab Next time