Experimental Psychology PSY 433

1
Experimental PsychologyPSY 433

• APA Format Reports
• Results, Discussion, References

2
Exam on Thursday

• Based on the textbook
• Covers all chapters and pages noted on syllabus
  (Ch 1-5 plus Appendix A pgs noted)
• No questions from labs
• No questions on APA format details
• Powerpoints provide an outline of what I
  considered important enough to discuss in class
  not a substitute for reading the book.

3
Projects Due in This Course

• Proposal similar to the kinds of proposals
  submitted to granting agencies.
• Contains parts of a full APA report plus extra
  info needed by the agency.
• Written in future tense.
• Final Report similar to the manuscripts
  submitted to journals for publication.
• Written in APA format.
• Written in past tense because it describes what
  happened.

4
Contents of Proposal

• Required for the assignment due 5/21
• Title Page
• Introduction
• Methods (written in future tense)
• References
• Proposals to granting agencies also include
• Bios of the researchers
• Budgets and performance timetables
• Lots of forms

5
Goals of a Research Proposal

• Convince the reader that the question is
  important and needs to be explored.
• Convince the reader that you are qualified to do
  the research (not part of the class project).
• Describe what research has occurred previously
  and what the competing theories are.
• Describe your plan for research in detail.
• Demonstrate that you have the resources to carry
  out the plan.

6
Introduction

• Start by stating your research question.
• Be specific, no general introductory remarks.
• Next, review the literature by summarizing
  previous research.
• At least 5 peer-reviewed sources required.
• Do not describe each article sequentially give
  an overview emphasizing what they found out.
• Conclude with a prediction about your own study
  stated in terms of theory.

7
Methods

• Include subsections, as described in the APA
  Manual
• Subjects (participants)
• Materials or apparatus (describe computer, your
  stimuli, any questionnaires).
• Procedures
• Describe design
• Tell what happened to the subject in
  chronological order
• Leave out things that happen in every experiment

8
Goals of the Final Report

• Communicate to the scientific community.
• Clearly describe your project in sufficient
  detail to permit replication.
• Convince readers that your findings support your
  conclusions.
• How strong is the evidence?
• Does it justify your statements about theory?
• Summarize your contribution to the ongoing debate
  on an important question.
• Pay special attention to your abstract!

9
Contents of Final Report

• Must contain all sections listed in the APA
  Publication Manual, including
• Title page
• Abstract
• Introduction
• Methods
• Results
• Discussion
• References
• Tables and Figures

10
You Are Telling a Story

• Introduction -- state your research question,
  review the literature, make your predictions
  (hypotheses).
• Methods describe how you explored the question
  in sufficient detail to permit replication.
• Results describe your findings and test your
  hypotheses using statistics.
• Discussion analyze your results and put them
  back into the context of your question.

11
Abstract

• This may be the only part of your paper that most
  people read, so make it count!
• Write this last.
• Tell the story of your study, with one sentence
  per report section.
• Do not exceed 120 words.

12
Use of Tenses

• For the final report, revise sections of your
  proposal because they will be graded again.
• Your proposal was written in the future tense
  (e.g., subjects will), but
• Put the Methods section in the past tense.
• Report your results in the past tense.
• Tense varies in the Introduction and Discussion.

13
Reporting Results

• Only include the results that are relevant to
  your research question, not all data collected.
• Go from the general to the specific.
• Provide tables for
• Multiple analyses.
• Complex experiments (factorial designs).
• ANOVA
• Organize your results section around your
  hypotheses, testing one at a time.

14
Describing Data

• Give both descriptive and inferential statistics.
• The mean number of words recalled was calculated
  for each group. The means and the standard
  deviations for each group are shown in Figure 1.
• Recall was higher for the drug group (M 15, SD
  5.43) than for the placebo group (M 10, SD
  4.98).

15
Reporting Statistics

• The data were analyzed using an independent
  t-test. The t-test showed no significant
  difference between the mean of the placebo group
  and the mean of the drug group, t(34) 1.35, p lt
  .05.
• Using two-way ANOVA, the main effect of gender
  was found to be significant, with females scoring
  higher on the average than males, F(1, 23)
  23.89, p lt .05.
• Better to show this analysis in a table.

16
Ethics of Reporting Statistics

• Dont change your hypotheses (prediction) to fit
  what you actually discovered. Instead say you
  were surprised.
• Decide how many subjects to test in advance.
• Dont stop collecting data because you already
  have significant results.
• Dont add more subjects because your results are
  almost significant and would become so with a few
  more subjects.
• Give your reason for ending data collection.

17
Avoid p-Hacking

• p-hacking is the practice of trying different
  approaches to data analysis until you find one
  that gives significant results. It is unethical.
• Collect at least 20 observations per condition.
• Report all experimental conditions, even failed
  manipulations (studies that didnt work).
• List all variables collected in a study, even if
  they are not analyzed in your paper.
• Report results with and without excluded
  subjects, covariates.

18
Changes in Reporting

• The internet is making possible different
  approaches to report writing.
• Because journals are no longer limited in space,
  authors can supply complete data sets, stimuli
  (materials) and alternative analyses.
• This represents a movement toward transparency.
• Exact vs conceptual replications are needed for
  marginal results.

19
References

• Format varies depending on the type of material
  being referenced (e.g., book, article, web site).
• Only list the sources actually mentioned in the
  text of your report.
• Everything listed in the references must be cited
  in text
• Everything cited in text must be listed in the
  references.
• When you mention a source referenced in another
  paper say as cited in and cite the source you
  actually read, not the original.

20
Tables and Figures

• Tables go first always use APA format.
• Figures are camera-ready original artwork that
  will be used by the publisher as is.
• Do not put page numbers, headers, figure captions
  or anything else on the front of the figure.
• Lightly write the figure number and short title
  on the BACK of each figure.
• Put all figure captions in a single list that
  appears before the figures.

21
Discussion

• First, state what you discovered during your
  experiment.
• Do not repeat results but state them in terms of
  the larger construct theory being tested.
• Tell whether your findings are consistent with
  what others have found.
• Describe any threats to validity and problems
  with your experiment (confounds, bias,
  limitations of generalizability, problems).
• Conclusion what are the consequences?