6. Research Methods (Experiments) Flashcards
What is an aim?
The general statement of what a researcher intends to investigate, the purpose of the study
What is a hypothesis?
A clear, precise, testable statement which states the relationship between the variables to be investigated
What is operationalisation?
Clearly defining variables in terms of how they can be measured
What are extraneous variables?
Any variable, other than the independent variable that may effect the dependent variable if not controlled
What are confounding variables?
A variable that varies systematically with independent variable
What are demand characteristics?
Any clue from the researcher/research situation that may be interpreted by participants, revealing purpose of investigation
What are investigator effects?
Any effect of the investigators behaviour (conscious or unconscious) on the research outcome
What is standardisation?
Using exactly the same formalised procedures and instructions for all participants in a research study
What are the 2 types of hypothesis?
- Directional: States the direction of the difference or relationship
- Non-directional: Does not state the direction of the difference or relationship
What is an experimental method?
Involves the manipulation of the IV to measure the effects on the DV
What is randomisation?
The use of chance methods to control the effects of bias when designing materials and deciding the order of experimental conditions
What are the 3 experimental designs?
1. Independent groups: participants allocated to different groups where each group represents one experimental condition
2. Repeated measures: all participants take part in all conditions of experiment
3. Matched pairs: participants in different conditions are paired together on variables relevant to the experiment
What is counterbalancing?
An attempt to control the effects of order in a repeated measures design
AO3 for independent groups
1. Less influence from order effects
2. Participant variables: variables differ between different groups, change in DV may be due to participants rather than effect of IV (confounding)
3. Less economical: twice as many participants needed to produce equivalent data to repeated measures, increased time/money on recruitment
AO3 for repeated measures
1. Order effects: repeating two tasks could create boredom/fatigue, deterioration in performance in second task HOWEVER performance may improve due to effects of practice, better performance on second task (confounding)
2. Demand characteristics: participants figure out aim of study when experiencing conditions
AO3 for matched pairs
1. Less influence from demand characteristics and order effects
2. Less economical: matching may be time-consuming and expensive
What are the 4 types of experiment?
- Laboratory experiment
- Field experiment
- Natural experiement
- Quasi-experiement
Describe a laboratory experiment
An experiment that occurs in a controlled environment within which the researcher manipulates the IV and records the effect on the DV
Describe a field experiment
An experiment that takes place in a natural setting within the researcher manipulates the IV and records the effect on the DV
Describe a natural experiment
An experiment which the change in IV is not brought about by the researcher but would have happened even if the researcher was not present
Describe a quasi-experiment
A study where the IV has not been determined by anyone, the variables simply exist e.g age
AO3 for laboratory experiment
- Highly controlled: lab experiments have high control over confounding and extraneous variables, certainty that effect on DV is a result of IV manipulation
- Easily replicable: result of high control, allows to check validity of results to ensure it is not one-off
- Lack generalisability: environment is artificial, does not reflect everyday life, low external validity
AO3 for natural experiment
- Opportunities for research: insight into areas not undertaken due to practical/ethical reasons
- High external validity
- Naturally occurring events are rare (low generalisability)
- Participants not randomly allocated (uncertain whether IV affected DV, may be due to differences)
AO3 for field experiment
- High mundane realism: more natural environment, produce valid and authentic behaviour as participants unaware they are being studied
- Loss of control over variables (confounding and extraneous): DV more difficult to establish, precise replication not possible
- Ethical issues: participants unaware they are being studied, cannot consent, lack of privacy
AO3 for quasi-experiment
- Controlled conditions (replication, objectivity)
- Confounding variables (cannot randomly allocate participants)
- Cannot claim IV has caused change (IV is not manipulated by experimenter)
How do confounding variables affect the findings of a study?
Difficult to tell if change in dependent variable is due to IV or confounding variable
What is the difference between population and sample?
- Population: A large group of people who are the focus of the researchers interest
- Sample: A smaller group of people drawn from the target population
What is bias in reference to sampling?
When certain groups are over or under represented within a chosen sample
What are the 5 sampling techniques?
- Random
- Stratified
- Systematic
- Opportunity
- Volunteer
What is random sampling + a strength and limitation?
- When all members of the target population have an equal chance of being selected
- Strength: unbiased
- Limitation: difficult/time-consuming to conduct
What is stratified sampling + a strength and limitation?
- When the composition of the sample reflects the proportion of people in certain sub-groups within the target/wider population
- Strength: representative sample (generalisability)
- Limitation: complete representation impossible (cannot reflect all ways people are different)
What is systematic sampling + a strength and limitation?
- When every nth member of a target population is selected
- Strength: objective (researcher has no influence over sample)
- Limitation: time-consuming
What is opportunity sampling + a strength and limitation?
- When researchers decide to select anyone who is willing and available
- Strength: convenient (cheap, less time consuming)
- Limitation: bias (unrepresentative of target population, researcher has complete control)
What is volunteer sampling + a strength and limitation?
- When participants select themselves to be part of the sample
- Strength: Less time-consuming
- Limitation: volunteer bias (may attract certain volunteers who are curious/wants to please researcher)
What are ethical issues?
A conflict between the rights of participants and the goals of a researcher to produce valid/authentic data
What are the 4 main ethical issues?
- Informed consent (making participants aware of the aims, procedure and their rights so they can make an informed judgement)
- Deception (deliberately misleading/withholding information at any stage)
- Protection from harm (protection from physical and psychological harm)
- Privacy/confidentiality (participants have the right to control their personal information)
How can the issue of informed consent be dealt with in an investigation?
- Participants required to sign a consent letter detailing all relevant information which may affect their decision to partake
How can the issue of protection from harm + deception be dealt with in an investigation?
- Participants given a full debrief (awareness of true aims/details)
- Right to withdraw/withhold data
- Counselling
How can the issue of privacy/confidentiality be dealt with in an investigation?
- Anonymity
What is a pilot study?
A small-scale version of an investigation that takes place before the real investigation is conducted
What are 2 aims of pilot studies?
- Allows the researcher to check that procedures, materials, measuring scales are working
- Allows the researcher to make necessary changes/modifications
What are single-blind procedures?
When certain data e.g aims/conditions of the experiment are withheld from participants at the beginning of the study
What are double-blind procedures?
When neither the participants nor the researcher who conducts the study is aware of the investigations aims
How are stratified samples allocated?
- Researcher identifies different strata that make up population
- Proportions needed for representative sample are calculated
- Participants that make up each stratum selected using random sampling
What is a sampling frame?
A list which the people in a target population are sorted into (used for systematic sampling)
