Psychology Chapter: Experimental Design

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Questions and Answers

What are two ways of minimizing extraneous variables?

Changing the IV

Standardised procedures (correct)

Increasing the sample size

Randomly assigning participants (correct)

What is a standardised procedure?

Ensure conditions set up the same way apart from changing the IV

What is social desirability bias?

When people want to look good so they act differently in a study

What are demand characteristics?

Participants change natural behavior because they know it's a study Signup and view all the answers

What is a confounding variable?

Variables that vary along with the IV Signup and view all the answers

What is the difference between directional and non-directional hypothesis?

Directional - predicts the direction of results; Non-directional - predicts there will be a difference between conditions Signup and view all the answers

What is a null hypothesis?

States there will be no significant effect in the study Signup and view all the answers

What are the types of experiments?

Laboratory, field, natural, and quasi experiments Signup and view all the answers

What is a laboratory experiment?

Environment controlled by experimenter and IV manipulated Signup and view all the answers

What is the evaluation for a laboratory experiment?

Strength: Have control, certain IV causes DV; High replicability; Weakness: Demand characteristics, artificial environment Signup and view all the answers

What is a field experiment?

In a natural setting, IV manipulated by researcher Signup and view all the answers

What is the evaluation for a field experiment?

Strengths: Less demand characteristics; High external validity; Weaknesses: Less control on extraneous variables; Ethical issues (deception) Signup and view all the answers

What is a natural experiment?

In natural environment, IV not manipulated by researcher Signup and view all the answers

What is the evaluation for a natural experiment?

Strengths: Genuine behaviour; Can study unchangeable variables; Weaknesses: No random assignment; More extraneous variables Signup and view all the answers

What is a quasi experiment?

In controlled environment, study based on existing IV (e.g., gender) Signup and view all the answers

What is the evaluation for a quasi experiment?

Strengths: Compare conditions impossible to manipulate; Weaknesses: Not possible to randomly allocate participants Signup and view all the answers

What is experimental design?

How the participants are allocated to conditions in an experiment Signup and view all the answers

What is repeated measures design?

Same participants used in both conditions Signup and view all the answers

What is a strength and weakness of repeated measures design?

Strength: No participant differences; Weakness: Order effects Signup and view all the answers

What is independent groups design?

Participants only take part in one condition Signup and view all the answers

What is a strength and weakness of independent groups?

Strength: No order effects; Weakness: Participant differences Signup and view all the answers

What is matched pairs design?

Participants are matched with a pair like them and then they are randomly allocated Signup and view all the answers

What is a strength and weakness of matched pairs design?

Strength: No order effects; Weakness: Time consuming and more participants required Signup and view all the answers

What is a representative sample?

A small group of people that characteristically represent the target population Signup and view all the answers

What are the different types of sampling techniques?

Random, opportunity, volunteer, systematic, stratified Signup and view all the answers

What is random sampling?

Everyone has an equal chance of being picked, e.g., pulling names out of a hat Signup and view all the answers

What is the evaluation of random sampling?

Pros: More representative, equal chance; Cons: May not be truly representative Signup and view all the answers

What is systematic sampling?

There is a system for selecting participants, e.g., putting names in order and picking every 5th person Signup and view all the answers

What is the evaluation of systematic sampling?

Pros: Avoids researcher bias; Cons: Fairly representative (unlikely to get all one gender) Signup and view all the answers

What is stratified sampling?

The target population is divided by factors and participants are selected to make the sample representative Signup and view all the answers

What is the evaluation of stratified sampling?

More representative - reflects target population; Cannot reflect all the ways people are different Signup and view all the answers

What is opportunity sampling?

Selecting people most ready, e.g., approach in a street Signup and view all the answers

What is the evaluation for opportunity sampling?

Convenient if no names available; Sample may be biased (in the same area) Signup and view all the answers

What is volunteer sampling?

Participants self-select themselves, e.g., replying to an ad in a newspaper Signup and view all the answers

What is the evaluation of volunteer sampling?

Only a particular type of person tends to volunteer Signup and view all the answers

What is qualitative and quantitative data?

Qualitative - words; Quantitative - numbers Signup and view all the answers

What is the evaluation for qualitative data?

Provides lots of detail; More difficult to analyze Signup and view all the answers

What is the evaluation for quantitative data?

Easy to analyze; Oversimplifies reality Signup and view all the answers

What are the three measures of central tendency?

Mean, median, mode Signup and view all the answers

What is the evaluation for the mean?

Utilizes all values; Affected by extreme anomalies Signup and view all the answers

What is the evaluation of median?

Not affected by extreme scores Signup and view all the answers

What is the evaluation of mode?

Useful when data is in categories; Sometimes multiple modes Signup and view all the answers

What are the two measures of dispersion?

Range, Standard Deviation Signup and view all the answers

What is the evaluation of primary data?

Strength - data matches research claim; Weakness - takes time and effort to collect Signup and view all the answers

What is the evaluation of secondary data?

Strength - quick, cheap, and easy; Weakness - may not completely match claim as not designed Signup and view all the answers

What is a pilot study?

Small trial of research, run before the real thing Signup and view all the answers

What is a strength of pilot studies?

Procedures, materials, and time length are checked; Saves money Signup and view all the answers

Where does a naturalistic observation take place?

Natural environment Signup and view all the answers

Where does a controlled observation take place?

Controlled environment, e.g., lab Signup and view all the answers

In what type of observation does the observer become part of the group studied?

Participant observation Signup and view all the answers

What happens in a nonparticipant observation?

Observer remains separate from the experiment Signup and view all the answers

What happens in a covert observation?

Participants don't know they're being studied Signup and view all the answers

What happens in an overt observation?

Participants know they're being studied Signup and view all the answers

What are the two methods of recording in an observation?

Time sampling and event sampling Signup and view all the answers

What is time sampling?

Recording what happens in a time frame e.g., every 30 seconds Signup and view all the answers

What is event sampling?

Making behavioral categories and counting how many times each occurs Signup and view all the answers

What is a behavioral category?

A type of behavior likely to be observed in the study Signup and view all the answers

What are some methodological issues of observations?

Difficulties in categorizing behaviors, observer bias, demand characteristics (if overt) Signup and view all the answers

What is a positive correlation?

Where the variables increase together Signup and view all the answers

What is the evaluation of correlational research?

Strength - can identify unchangeable variables; Weakness - cannot establish cause and effect Signup and view all the answers

What is a negative correlation?

One variable increases as the other decreases Signup and view all the answers

What does a positive distribution look like?

Data spread to the left, e.g., easy test Signup and view all the answers

What does a negative distribution look like?

Data spread to the right, e.g., hard test Signup and view all the answers

Where are the mean, median, and mode on a distribution?

Mode at the peak; Mean on right for positive and left for negative; Median in between mean and mode Signup and view all the answers

Where are the mean, median, and mode in a normal distribution?

All at the peak Signup and view all the answers

What are the five ethical issues?

Informed consent, deception, right to withdraw, privacy/confidentiality, protection from harm Signup and view all the answers

What can you do at the end of an experiment to avoid most ethical issues?

Debrief the participants Signup and view all the answers

What is it called when you get consent from similar participants?

Presumptive consent Signup and view all the answers

What are the two types of self-report?

Questionnaires and interviews Signup and view all the answers

What are the strengths of interviews?

Misunderstandings can be clarified, less likely to miss out on a question, participants more honest with interviewer Signup and view all the answers

What are the weaknesses of interviews?

Time consuming, expensive, investigator effects, social desirability bias Signup and view all the answers

What are the strengths of questionnaires?

Quick, cheap, easy, no investigator effects, ethical Signup and view all the answers

What is peer review?

Validating new research by peers in the same field Signup and view all the answers

What are the aims of peer review?

Allow research funding, validate quality of research, make improvements Signup and view all the answers

What are biases in peer review?

Objectivity (opinion), anonymity, publication bias Signup and view all the answers

What are the weaknesses of questionnaires?

Biased sample, untruthful answers, misunderstandings not clarified Signup and view all the answers

What is observer bias?

When the observer's expectations influence their interpretation of the participant's behavior Signup and view all the answers

What is inter-rater reliability?

The degree of agreement between different observers rating the same behaviors Signup and view all the answers

What is a double-blind procedure?

When both participants and researchers are unaware of who is in the experimental or control group Signup and view all the answers

What is a control group?

The group in an experiment that does not receive the treatment and is used as a comparison for evaluating the effect of the treatment Signup and view all the answers

What is a placebo effect?

When participants' expectations, rather than the actual treatment, produce an outcome Signup and view all the answers

Study Notes

Minimizing Extraneous Variables

Use standardised procedures to ensure consistency across conditions.
Randomly assign participants to reduce biases.

Standardised Procedures

Establish uniform conditions for an experiment, varying only the independent variable (IV).

Participants may alter their behavior to appear favorable or socially acceptable during studies.

Demand Characteristics

Participants modify their natural behavior due to awareness of being observed in a study.

Confounding Variable

Variables that fluctuate alongside the independent variable, potentially skewing results.

Hypotheses

Directional Hypothesis: Predicts the specific direction of results.
Non-Directional Hypothesis: Indicates a difference will occur without specifying direction.
Null Hypothesis: Asserts no significant effect exists within the study.

Types of Experiments

Laboratory Experiments: Highly controlled environments where IV is manipulated.
Field Experiments: Conducted in natural settings; IV is still manipulated by researchers.
Natural Experiments: Observe outcomes in natural environments without IV manipulation.
Quasi Experiments: Investigate existing variables in controlled settings, like gender.

Evaluation of Experimental Types

Laboratory Experiments: Strength in control and replicability, weakness in artificiality inducing demand characteristics.
Field Experiments: Strength in ecological validity, weakness in lack of control over extraneous variables.
Natural Experiments: Strength in observing genuine behavior; weakness in potential for extraneous variables and lack of random assignment.
Quasi Experiments: Allows comparison of manipulated conditions, but lacks the ability for random allocation.

Experimental Designs

Repeated Measures Design: Uses the same participants in all conditions, minimizing participant differences, but susceptible to order effects.
Independent Groups Design: Each participant is in only one condition, avoiding order effects but leading to potential participant differences.
Matched Pairs Design: Participants are paired based on similarities and randomly assigned, eliminating order effects but requiring more time and participants.

Sampling Techniques

Representative Sample: A small group reflecting the traits of the target population.
Random Sampling: Every individual has equal chances of selection, enhancing representativeness but possibly leading to randomness.
Systematic Sampling: Participants selected using a fixed interval, potentially avoiding bias but may not capture all demographics.
Stratified Sampling: Population divided, with participants chosen to represent specific sub-groups, enhancing representation but complexity in reflecting all variables.
Opportunity Sampling: Selecting readily available individuals, convenient but risk of a biased sample.
Volunteer Sampling: Individuals choose to participate, potentially attracting a specific demographic.

Data Types

Qualitative Data: Expressed in words, rich in detail but harder to analyze.
Quantitative Data: Expressed in numerical format, easier to analyze but may oversimplify reality.

Measures of Central Tendency

Mean: Average, sensitive to extreme values.
Median: Middle score, unaffected by extremes.
Mode: Most frequent, beneficial for categorical data.

Measures of Dispersion

Range: Difference between highest and lowest scores.
Standard Deviation: Indication of data spread around the mean.

Data Evaluation

Primary Data: Matches research claims but requires significant effort.
Secondary Data: Quick and easy to obtain but may not align with specific research needs.

Pilot Study

Conducted as a small-scale trial to test research methods, saving time and resources.

Observation Types

Naturalistic Observation: Occurs in real-world settings.
Controlled Observation: Takes place in a structured environment, like a lab.
Participant Observation: Researcher engages with participants in their environment.
Nonparticipant Observation: Researcher remains separate from the group.
Covert Observation: Participants are unaware they are being observed.
Overt Observation: Participants know they are part of a study.

Recording Methods in Observations

Time Sampling: Observing and recording behaviors within specified time intervals.
Event Sampling: Counting occurrences of defined behaviors over a study.

Correlation

Positive Correlation: Both variables increase together.
Negative Correlation: One variable increases as the other decreases.
Correlation Research Evaluation: Useful for studying unchangeable variables; however, it does not establish causation.

Distribution Types

Positive Distribution: Data clustered to the left, indicating easier performance.
Negative Distribution: Data clustered to the right, indicating difficult performance.
Normal Distribution: Equal mean, median, and mode at the peak.

Ethical Issues

Informed consent, deception, right to withdraw, privacy/confidentiality, and protection from harm must be considered.

Self-Report Methods

Interviews: Allow clarification and depth but can be time-consuming and susceptible to biases.
Questionnaires: Quick and ethically sound but may yield biased samples.

Peer Review

Process of validating research by other experts in the field to maintain research quality.

Reliability and Bias

Observer Bias: Expectations influence the interpretation of behaviors.
Inter-Rater Reliability: Agreement level between observers evaluating the same behaviors.
Double-Blind Procedure: Both participants and researchers are unaware of the group assignments to reduce bias.

Control Group

Serves as a comparison for evaluating treatment effects without receiving the treatment.

Placebo Effect

Outcomes influenced by participants' expectations rather than the actual treatment.

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Description

This quiz covers essential concepts in experimental design within psychology, including minimizing extraneous variables, standardised procedures, and biases. Test your understanding of hypotheses and different types of experiments. Ideal for students looking to reinforce their grasp of research methods.