AICE Psych: Research Methods

Paper 2 AICE Psychcology Test Prep

Identify the main features of an Experiment.

• Must have both an IV (Independent Variable; what’s being changed/manipulated) and a DV (Dependent Variable; what’s being measured)

• Data collected from an experimental group and a control group

• Standardised procedure amoungst participants

What is a labratory experiment?

An experiment conducted in an artificial/controlled setting (usually a lab).

State the strengths of the usage of laboratory experiments.

• There are lots of controls for possible extraneous variables

• Cause and effect can be inferred due to the controlled environment

• Standardised procedures

State the weaknesses of the usage of laboratory experiments.

• Low ecological validity; cannot replicate a real-world scenario because of the highly controlled environment

• Demand characteristics could alter results

What is a field experiment?

An experiment that is conducted in the natural environment of the participants.

State the strengths of conducting a field experiment.

• High ecological validity: The experiment is done in the participant’s natural environment, so it allows for the collection and observation of natural behaviors/reactions to the IV.

State the weaknesses of conducting a field experiment.

• Researchers have limited control over extraneous variables in the study; this makes it hard to standardize the procedure, resulting in low reliability.

• Oftentimes, participants do not know they are a part of an experiment, so informed consent cannot be collected, and the right to withdraw cannot be offered.

Outline what an independent measures design is.

An experimental design where the participants only experience one level of the offered IV.

• Normally, participants are in two groups: one is the experimental (with the manipulated IV), and the control (without the manipulated IV).

Outline what a repeated measures design is.

An experimental design where the participants experience all levels of the offered IV.

• They can experience both the control and experimental conditions.

What are demand characteristics?

Cues in the set-up of an experiment, including how the researcher acts or speaks, provide clues into the aim/hypothesis of the study.

• Sometimes, participants will alter their behavior due to these characteristics, altering the true results of the study.

Describe random allocation.

Participants are randomly put into the experimental or control conditions for the experiment.

• Participant variables are more likely to occur: participants randomly allocated are likely to have shared participant variables.

  • Definition: variables that vary across participants, things like age, gender, etc.

Outline what the practice effect is.

Participants may perform better on a task they’ve already experienced the second time, due to the experinece gained in the first task

Outline what the fatigue effect is.

Participants may perform worse on a task due to boredom, tiredness, or strain of concentrating on the previous task

Outline what order effects are, and the weaknesses of them.

Def: When participants have to complete a task multiple times under different conditions, behavior in later conditions may differ from that in the first condition, not because of variable manipulation, but because they have already completed the required task.

• e.g., practice and fatigue effect

Weakness: are a threat to a study’s validity, because it becomes unclear whether the behaviors participants exhibit are due to the manipulation of the situationa nd variables or due to the task they were required to complete.

• Can be reduced by using counterbalancing/waiting a period of time before trials

Outline what is meant by ‘counterbalancing’ and provide an example.

• Used in repeated measures design experiments: so order effects don’t compromise validity

Participants are put into one of two groups: group one does the experimental condition first, and then the control condition. Group two does the control condition first and then the experimental condition.

• Order effects may still arise, but they won’t compromise the findings as much

EX: Perry et al. counterbalanced the oxytocin and placebo IV condition(s)

Define ‘matched pairs design’ and outline one strength and one weakness of this design.

When each participant in the experimental condition is matched with each participant in the control condition on various factors.

• Both groups will have another participant who is very similar to them in ways to not compromise the dependent variable(s)

Strength: Able to overcome the possibilities of participant variables and order effects

Weakness: Difficult to carry out as careful screening is necessary to match groups, and it may be difficult to recruit individuals with similar characteristics.

Pozzulo et al. used a repeated measures design, so children observed both human and cartoon faces, and participated in both target-absent and target-present line-ups.

Suggest one advantage of a repeated measures design with reference to the study.

Advantage: Participant variables cannot affect the validity of results, as every participant experiences all levels of the IV/ both the experimental and control conditions.

Reference: Researchers can see the comparison between the results of the dependent variable of correct identification of the children analyzing either human or cartoon faces in target-present or target-absent line-ups without the possibility of participant variables interfering.

In Piliavin et al. (Subway Samaratins), the researchers observed train passengers’ reactions to a staged emergency. This study used independent measures.

Explain one disadvantage of this design using an example from this study.

Disadvantage: When there are multiple levels of the IV, it may be difficult for the researchers to compare the results of each level with various participants, especially if participant variables are present.

Example: Piliavin had multiple conditions of the IV: race, condition, model, and group size. Helping behavior may have differed due to participant variables across the IV, and may be difficult to generalize and compare to the control group.

Javine thinks ink color (red or black) might affect the speed at which participants can complete an anagram. She decides to use a laboratory experiment with a repeated measures design.

a) Explain how practice effects could affect the validity of the study.

b) Explain how Javine could use counterbalancing to improve the study.

a) As participants complete the task of using red or black ink, they may complete the second anagram faster due to the completion of the first one previously, regardless of the ink type.

b) She could have participants complete the red pen condition, while the other group completes it with the black pen condition. Wait 24 hours, and have the red pen condition complete the task with the black pen condition and vice-versa.

Outline what is meant by a ‘Randomised control trial.’

A special type of experiment that uses various techniques to improve the validity of the study, and is often referred to as the ‘golden standard’ in clinical and health research, like drug testing.

• e.g., Participants may be randomly assigned to an experimental (receiving a new drug) or a control group (given a placebo).

Outline the ‘placebo effect,’ and give an example.

Participants in a control condition receive an administration of a treatment the same way the true treatment is administered to the control group, but it doesn’t contain the same active ingredients.

• Normally, the ‘single-blind’ procedure is used: only the participant is unaware of the treatment they’re receiving.

  • e.g., Participants in Perry et al. received either a placebo saline solution or an oxytocin solution.

Outline the ‘double blind’ design, and outline a strength of it.

Neither the participant nor the researcher knows which solution (placebo or actual drug) was administered to the participant.

Strength: When researchers are outlining the procedure for the participants, there is no researcher bias due to the understanding of the solution they received. Assessment of the participant remains objective.

Evaluate the usage of RCT’s (Randomised Controlled Trials) in terms of validity, reliability, and ethicality.

Validity: High: Reduces experimenter bias as well as demand characteristics.

Reliability: High: allows researchers to test interventions in a controlled way.

Ethicality: Valid, Informed consent is not possible:

Potential psychological harm:

Outline what a self-report is.

Participants respond to either open or closed questions regarding various topics; can collect quantitative or qualitative data.

Identify strengths and weaknesses of using questionnaires in psychological research.

Strengths:

• Relatively quick and easy to gain information from a large number of participants; the large sample size can also increase generalizability

• Less likely to give socially desirable answers in an interview because of the face-to-face contact with the researcher

Weaknesses:

• Participants may be less willing to elaborate on open quesiton answers, limiting the detail of data collected

• May give socially desirable answers on a self-report, which can not accurately represent the participants’ reactions or responses to the stimuli of the study.

Outline an advantage and disadvantage of using open-ended questions.

Advantage: Data is qualitative, so the responses are rich in detail, which can provide more insight for the researchers.

Disadvantage: Data can be harder to analyze, as the description in words of various stimuli may be hard to interperate across reserachers

Outline an advantage and a disadvantage of using closed-ended questions.

Advantage: Data is quantitative and can be analyzed objectively using various measures of central tendency.

Disadvantage: Limited choices reduce validity; participants aren’t able to freely express their feelings/opinions on various topics.