1. 9
Procedure for Conducting an Experiment

2. Institutional Approval
Institutional Animal Care and Use Committee (IACUC)
reviews research protocols for studies using nonhuman animals
determines if proposed procedures are ethical
e.g., avoid or minimize pain and discomfort
Institutional Review Board (IRB)
reviews research protocols for studies using human participants
primary concern is participant welfare
has informed consent been obtained?
do potential benefits of study outweigh risks to participants?

3. Research Participants
Chosen participants depends on research question
obtaining animals
albino variant of brown rat is most commonly used
the Animal Welfare Act regulates care and housing
the Guide for the Care and Use of Laboratory Animals (1996) provides a guide to using animals appropriately

4. Research Participants
Obtaining human participants
recruitment depends on type of participant needed
examples
research question dictates homeless participants then you would contact homeless shelters and visit areas frequented by homeless individuals
research question dictates school children as participants then you would contact schools and possibly pediatricians’ offices
convenience sample of college students often used in psychological research
may not be representative of target population

5. Research Participants
Obtaining human participants
using the Internet to recruit research participants is becoming more common
advantage
providing access to a larger and more diverse sample than otherwise possible
disadvantage
select groups may not have access to Internet (e.g., disabled)
sample may not be representative of target population
No matter how participants are recruited
important to report how participants were selected and assigned to research conditions (methods section)

6. Sample Size
How many research participants should be included in the research?
practicality must be balanced with the increased power that accompanies a large sample

7. Power The probability of correctly rejecting the null hypothesis
Correctly saying the treatment conditioned produced an effect
Power of at least .80 is desired
i.e., we want to correctly reject a false null 80% of the time
Factors that influence power
sample size
as sample size increases, power increases
so does time and money required to complete research
alpha level
for now, all you need to know is that alpha is set at 0.05
effect size
the magnitude of the relationship between two variables in a population
can be estimated at small, medium, and large
examine literature for approximate effect size estimation
Should conduct Power Analysis to estimate sample size

8. Power Analysis

9. Apparatus and/or Instruments
How will independent variable be manipulated and how will dependent variable be measured?
depends on nature of research
may involve active participation by researcher
example – Langhinrichsen-Rohling and Turner (2012)
a particular type of apparatus
examples – computers, MRI, EEG
Behavioral Research Methods is a good source to identify research instruments

10. Procedure and Scheduling
detailed description of how experiment will be conducted
important to allow for future replication
Scheduling of research participants
availability of the researcher and participants
anticipate drop out rates with human participants

11. Consent to Participate
Informed consent necessary unless waived by IRB
Consent form should include the following elements:
basic information about the study
details about procedure of study including possible risks
any potential benefits that might be derived
the type of compensation provided and compensation penalty for early withdrawal
for sensitive topics (e.g., depression, abuse) extra information for individuals who need assistance
participants must be informed that they can withdraw from study at any time without penalty
if using questionnaire, a statement indicating that participant can refuse to answer any question without penalty
participants must be informed as to how the records and data obtained will be kept confidential

12. Instructions and Data Collection
should be precise, but not overly complex
refrain from certain phrases
“pay attention”, “relax”, and “ignore distractions”
language should be simple and on the level of the participant
warm-up trials can assess understanding of instructions
Data collection
follow design

13. Debriefing Functions ethical educational methodological
undo any deception involved in study
decrease stress or risk if possible
attempt to return participants to pre-experimental state
particularly important if deception is used
educational
this mostly applies to students participating in research for class credit
methodological
to establish effectiveness of independent variable or deception
to judge accuracy of participations’ suspicions and perceptions
sense of satisfaction
participant feeling as if they contributed to science and society

14. Debriefing How to debrief face to face generally preferred
begin by asking if participant has questions
question participant to determine if all aspects of study were clear
if deception was used
attempt to determine if participant discerned true nature of study
explain the purpose of using deception
ask participant not to reveal details of experiment to other participants

15. Pilot Study
A brief run-through of the entire experiment with a few participants prior to the actual collection of data
Serves several purposes:
establishes clarity of instructions
provides evidence that independent variable is being manipulated adequately
familiarizes researcher with the procedure