Research methods year 1 Flashcards
What is the aim?
a general statement of what the researcher intends to investigate
What is a hypothesis?
A testable prediction about the variables in a study. It should always contain the IV and the DV
What is a directional hypothesis?
A one-tailed hypothesis that states the direction of the difference or relationship
What is a non-directional hypothesis?
A two-tailed hypothesis that does not predict the direction of the difference or relationship
What is operationalisation
Clearly defining variables in terms of how they can be measured
What is the independent variable?
The variable that the researcher manipulates and is assumed to have a direct effect on the DV
What is the dependent variable?
The variable that the researcher measures. It is the variable that is affected by the manipulation of the IV
What is an extraneous variable?
Any variable, other than the IV, that may affect the DV if it is not controlled
What are the four types of extraneous variables
Participant variables, situational variables, investigator effects and demand characteristics
What are situational variables?
factors in the environment that can unintentionally affect the results of a study
Give examples of situational variables (7)
heat, noise, distractions, time of day, time of year, place in history, order effects
What are participant variables?
Characteristics of individual participants that might influence the outcome of a study
Give examples of participant variables (10)
Age
Gender
Mood
Ethnicity
Expectations
Intelligence
Personality
Memory
Previous experience
Participant reactivity
Why does research need to be highly controlled
To avoid the effects of extraneous variables
What are confounding variables?
Variables that vary systematically with the IV. Therefore we can’t tell if any change in the DV is due to the IV or the confounding variable
What are demand characteristics?
Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of the investigation, and change participants’ behaviour
What is the please-U effect and the screw-U effect?
When participants act in a way that they think is expected and over-perform to please the experimenter
When participants deliberately under-perform to sabotage the results of the study
What are investigator effects?
Any effect of the investigator’s behaviour (conscious or unconscious) on the research outcome (the DV)
What is randomisation?
The use of chance methods to control for the effects of bias when designing materials and deciding the order of experimental conditions
controlling situational variables - standardisation
Using exactly the same formalised procedures for all participants in a research study
What are standardised instructions?
A set of instructions that are the same for all participants so as to avoid investigator effects caused by different instructions
what is an experiment?
A controlled situation in which the researcher manipulates one variable to discover its effect on another variable, while the other variables are held constant
What is the independent groups design?
Participants are allocated to different groups where each group represents one experimental condition
Advantages of independent groups design (2)
• No order effects - participants are only tested once so can’t practise or become bored/tired. Controls an important CV
• Will not guess aim - participants are only tested once so they are unlikely to guess the research aims. Behaviour may be more ‘natural’ (higher realism)
Disadvantages of independent groups design (2)
• The participants in the two groups are different, acting as EV/CV - If researcher finds a mean difference between the groups on the DV this may be more to do with participant variables than the effects of the IV. Reduces the validity of study
• Less economical - need twice as many participants as repeated measures for the same data. More time spent recruiting, expensive
What is the repeated measures design?
All participants take part in all conditions of the experiment
Advantages of repeated measures design (2)
• Participant variables are controlled - The person in both conditions has the same characteristics. This controls an important CV, higher validity.
• Fewer participants - Half the number of participants is needed than in independent groups. Less time spent recruiting participants.
Disadvantages of repeated measures design (2)
• Order effects - participants may do better or worse when doing a similar task twice. Also practice/fatigue effects. Reduces the validity of the results
• Can guess aims - Likely that participants will work out the aim of the study when they experience all conditions of the experiment. May change their behaviour. This may reduce the validity of the results
What is the matched pairs design?
Pairs of participants are first matched on some variables that may affect the DV. Then one member of the pair is assigned to condition A and the other to condition B
Advantages of matched pairs design (2)
• Participant variables are controlled - Participants are matched on a variable that is relevant to the experiment. This enhances the validity of the results
• No order effects - participants are only tested once so no practice or fatigue effects. Enhances the validity of the results
Disadvantages of the matched pairs design (2)
• Matching is not perfect - time-consuming and can’t control all relevant variables. Can’t address all participant variables.
• Need twice as many participants as repeated measures for the same data. More time is spent recruiting, expensive
What is random allocation?
An attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other
What are order effects?
A confounding variable arising from the order in which conditions are presented
What is counterbalancing and why is it needed in repeated measures design experiments
An attempt to control for the effects of order: half the participants experience the conditions in one order, and the other in the opposite order
What participants do at the start of a test could influence how they perform later in the test
Types of experiment - What is a laboratory experiment? (3)
A controlled environment where EVs and CVs can be regulated
Participants go to the researcher
The IV is manipulated and the effect on the DV is recorded
Advantages of laboratory experiments
EVs/CVs can be controlled - this means that the effect of EVs and CVs on the DV can be minimised. Cause and effect between the IV and DV can be demonstrated (high internal validity)
Disadvantages of laboratory experiments (2)
Demand characteristics may be a problem - cues in the experimental situation that invite a particular response from participants. Findings may be explained by these cues rather than the effect of the IV (lower internal validity)
Types of experiment - what is a field experiment?
Conducted in a natural setting
The researcher goes to participants
The IV is manipulated and the effect on the DV is recorded
Advantages of field experiments
More natural environment - Participants are more comfortable and behaviour is more authentic. Results may be more generalised to everyday life
Disadvantages of field experiments
Ethical issues - May not have given consent. Invasion of their privacy
Types of experiment - what is a natural experiment?
An experiment where the change in the IV is not brought about by the researcher but would have happened even if the researcher had not been there. The researcher records the effect on a DV they have decided on.
What are the advantages of natural experiments
May be the only practical/ethical option - May be unethical to manipulate the IV. A natural experiment may be the only way casual research can be done for such topics
What are the disadvantages of natural experiments (2)
Participants are not randomly allocated - experimenter has no control over which participants are placed in which condition as the IV is pre-existing. May result in CVs that aren’t controlled
Types of experiment - what is a quasi-experiment?
IV is based on a pre-existing difference between people, e.g. age or gender. No one has manipulated this variable, it simply exists. DV may be naturally occurring or may be devised by the experimenter and measured in the field or lab
What are the advantages of quasi-experiments
The IV is a difference between people. this means that comparisons between different types of people can be made
What are the disadvantages of quasi-experiments
Participants are not randomly allocated - the experimenter has no control over which participants are placed in which condition as the IV is pre-existing. Participant variables may have caused the change in DV acting as a CV
why should the sample that is drawn be representative of the population
so generalisations can be made
What is the population
A group of people who are the focus of the researcher’s interest, from which a smaller sample is drawn
Why is a sample needed
it is usually not possible to include all members of the population in the study, so a smaller group needs to be selected
What is a random sample?
A form of sampling in which all members of the target population have an equal chance of being selected
Describe the steps of selecting a random sample (3)
• A complete list of all members of the target population is obtained
• All of the names on the list are assigned a number
• The sample is selected through the use of a lottery method e.g. picking numbers from a hat
Strengths of random sampling
All members of the population have an equal chance of being chosen - high population validity
Weakness of random sampling (2)
Difficult and time-consuming to conduct - a complete list of the target population may be extremely difficult to obtain
What is a systematic sample?
When every nth member of the target population is selected
How is systematic sampling carried out (3)
• a sampling frame is produced - a list of people in the target population organised into e.g. alphabetical order
• a sampling system is nominated e.g. every 3rd person
• researcher works through the sampling frame until the sample is complete
Strength of systematic sampling
• objective - once the system for selecting has been established, the researcher has no influence over who is chosen
Weakness of systematic sampling (2)
• time consuming
• Participants may refuse to take part
What is a stratified sample?
A form of sampling in which the composition of the sample reflects the proportions of people in certain subgroups (strata) within a population
How is stratified sampling done (3)
• subgroups (strata) are identified, e.g. gender or age groups
• the proportions needed for the sample to be representative are worked out
• the participants that make up each stratum are selected using random sampling
Strength of stratified sampling
representative method - it is designed to accurately reflect the composition of the population, generalisation of findings becomes possible
Weakness of stratified sampling (2)
• the identified strata cannot reflect all the ways in which people are different
• complete representation of the target population is not possible