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Explore the ethical considerations in research, from participants' rights to informed consent, deception, and more. Learn about the IRB process, submitting protocols, and the importance of informed consent in research studies.
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Ethics of Research - Review and Application + Some “Catch-up” Items Lawrence R. Gordon Psychology Research Methods I
Bystander Response to Arterial Bleeding • Shotland & Heinold (1985) • Research question? • Methodological issues (relating to participants’ rights, informed consent, deception, etc.) • Overall YEA/NAY? • Revisions?
Southern Culture of Honor • Cohen, Nisbett, Bowdle, & Schwarz (1996) • Research question? • Methodological issues (relating to participants’ rights, informed consent, deception, etc.) • Overall YEA/NAY? • Revisions?
WHY REVISIT THIS NOW? • You are about to conduct research at UVM • We want you to know more about the local process • You have learned more since the earlier introduction that may provide a context • Resources: UVM Human Subjects site: • http:/www.uvm.edu/~reshmpg/test/irb-home.htm • http://www.uvm.edu, then Research, Human Subjects
What Does the IRB Do? • Its chief function: Considers costs and benefits of the research • Asks, is the research question worth the use of human participants? • Because human participants do not need to participate in studies, their rights are the highest priority
Submitting Protocols • In general --- wide range • As part of a class • Exempt from review • Expedited review • Full review: IRB meetings • Strong focus on Informed Consent • Lay summary • Consent Form • Often combined
Lay Summary • No jargon! (hence “lay”) • Elements: • Title • Invitation to participate • Aims - hypothesis • Background - WHY conducted • Procedures - include time commitment • Risks/Discomforts/Inconveniences • Benefits - personal & societal • Costs • Many optional elements
Statement of Consent • Elements • Have read lay summary • Understand procedure, risks, and benefits • Participation voluntary; may withdraw any time • Confidentiality to extent of the law • Whom to contact if questions • Signature • Sometimes sign certifying a debriefing was given • Example of combined form -- Goodwin p. 50 • For simple exempt study not terribly complicated
Issues or questions? • Yes? No? • Then we’ll move on to some further ideas in statistics that may be of help in understanding your analyses and output
Some ideas behind the statistics • Nature of “test statistics” (vs. descriptive) • e.g., t and F, so far…. • Suppose the null hypothesis is true, what is the value of “Treatment”? • Suppose “Treatment”=0, what is the value of TestStat? • What happens as “Treatment” gets larger: to TestStat? to prob(TestStat|Null true) -- “p=”?
Some ideas behind the stats (cont.) • What is this “df” thing? • E.g., , for n scores • df = n-1 here, why? what’s it mean? • Kinda “techie,” but if the mean, X-bar, is known, then only n-1 scores are “free to vary,” hence only n-1 “degrees of freedom” or “df” • Example -- suppose you know the mean of 3 scores is 10, then if 2 are: the third must be: 12, 8 ? 8,7 ? 13, 12 ?
So, df in articles, etc.? Can be useful... • For independent groups means --- • t(28) means there were 30 scores, because for this, df=(n1-1)+(n2-1)= n1+n2-2 • For paired means (repeated measures) • t(28) means there were 29 pairs of matched scores, df = n-1 pairs of related scores • Examples (blasts from the past)...
ANSWERS REVISITED“Having Fun” Example Inferential Statistics
Repeated-measuresDefinitional Example • “Family therapy for anorexia” (1994) • SPSS -- standard analysis for paired-samples:
So, df in articles, etc.? Can be useful…(continued) • For k independent groups means --- • “F(2,24)” means that there were • 3 levels of the IV “Effect” df = k-1 • 24 “df for error” ”Error” df = 24 here • 27 scores in all Effect df + Error df = N-1 Sourcedf Effect 2 Error 24 Total 26 • If equal size groups, how many Ps per group? • Example... “F(2,215)=5.314”
So, df in articles, etc.? Can be useful... (continued) • For k levels in repeated-meas ANOVA --- • F(2,24) means that there were • 3 levels of the IV “Effect” df = k-1 • 24 “df for error” ”Error” df = 24 here • Error = 2(n-1)=24, so n-1=12 13 Participants! • ?? scores in all Ss df + Effect df + Error df = N-1 Source df Subjects n-1 Effect k-1 Error (n-1)(k-1) Total nk-1 = N-1 scores • Example... “F(3,69)=5.60”
Mandel et al. (1995), from Handout last class: “Listening times to sound stimuli” • “Across all 24 subjects {itemized values of 4 means}…an [ANOVA] revealed …{means}were significantly different with a main effect of name category, F(3,69)=5.60, p=.0017.” • ANOVA Summary Table Source df SS MS F p Subjects 23 Listen Time 3 5.60 .0017 Error 69 Total 95 For “F(3,69), how many scores were there? 3+69=72 + 24 Ss = 96 (24 Ss x 4 scores each!) • EXAMPLE (SPSS -- Memory)…”F(2,434)=27.562”
MEM 2001: Within-Ss N=200 Ps
Some ideas behind the Statistics…POWER • Recall the abstract definition of a test statistic: • We want to find effects if they’re there, and Power is the probability of doing that. • The larger the test statistic, the greater our chance of doing that. • Therefore, we want to maximize the numerator and minimize the denominator, but how?
Influences on Power of the NHST … Pr(Reject null|Null false) • Level of significance used (); e.g. more power if .05 than if .01 (set a priori) • Size of the treatment effect: more power if larger effects (increase numerator) • Size of the sample: more power if N larger (decrease denominator by increasing df for error) • Experimental control and procedure (increase power by decreasing error variability in denominator) • Choice of design -- often within-Ss more powerful by reducing individual differences -- “error variance” • Review Goodwin pp. 136-141.
WRAPUP • Will go on to final major experimental design next two classes --- factorial designs and their interaction effects. Extremely important --- most frequently used designs!