Flashcards in Research methods Deck (82)
The manipulation of an independent variable to measure the effect on the dependent variable. May be laboratory, field, natural or quasi.
Making variables measurable
A clear precise statement that states the relationship between the variables to be investigated. Stated at the outset of any study
eg, Drinking fizzy drinks cause people to become more talkative
direction of the difference or relationship
eg. people who drink fizzy drinks become more talkative then people who don’t
People who drink water are less talkative then people who drink fizzy drinks
used when there are previous studies that suggest a particular outcome
non directional hypothesis
does not state the direction
eg Eg people who drink fizzy drinks differ from people who don’t drink fizzy drinks
used when there are no previous studies to suggest a particular outcome
Any “thing” that can vary or change within an investigation. Variables are generally used in experiments to determine if changes in 1 thing result in changes in another.
A general statement of what a researcher intends to investigate
are unwanted variables that need to be controlled for both experiments otherwise will interfere with the IV or DV eg Noise, temperature, amount of sleep, personality. It MIGHT mess with results not a very big deal.
-Participant variables: are any individual differences between participants that may affect the DV
-Situational variables: any features of the experimental situation that may affect the DV
same participants doing both conditions
independent group design
two groups of participants doing both designs
change systematically with the IV so we cannot be sure if any observed change in the DV is due to the confounding variable or the IV, so results are meaningless
- eg if there were two groups and one group were introverts and the other were extroverts this would result in a 2nd unintended IV and so you don’t know if fizzy drink affected the 2nd group because they were already extroverted – personalities is the confounding variable
refers to any clue from the researcher or research situation that may reveal the aim of the study.
- In a study the participants will try to work out what is going on trying to find demand characteristics. The participants may act in a way they think is expected overperforming (please- U effect) or underperforming (screw-U effect).
are any effect of the investigator’s behaviour on the outcome of the research (the DV)
- eg given that they researcher was expecting the energy drink group to speak more than the water group and unknowingly in our unconscious behaviour encourage a greater level of chattiness from the energy drink participants.
the use chance when designing investigations to control for the effects of bias and minimise the effect of extraneous/ confounding variables.
-eg a memory experiment may involve participants recalling words from a list. The order of the list should be randomly generated so that the position of each word is not decided by the experimenter.
Using exactly the same formalised procedures for all participants in a study
- all participants should be subject to the same environment, information and experience so all procedures are standardised.
standardised instructions example
this includes standardised instructions that are read to each participant. Example:
Thank you for participating please sign this form of consent. You have the right to withdraw at any point throughout the investigation it will take an hour of your time and you have 30 minutes to drink a liquid on the table in front and then I shall interview you for 20 minutes. Thank you for participating.
are used for a purpose of setting a comparison and acct as a ‘baseline’ and help establish causation.
is where a participant doesn’t know the aims of the study so the demand characteristics are reduced.
both participants and researcher don’t know the aims of the study to reduce demand characteristics and investigator effects.
Same participants doing both conditions
Problem: They may have had practise or be too fatigued (order effects) – reduces validity of results
-participants may guess aims - reduces validity of results
Good: there are no individual differences between participants – controls important CV
-fewer participants – wastes less time
Independent groups design
The two groups of participants doing both conditions
Problems: there are individual differences between participants -reduce validity of study
-more participant – more money spent and time wasted recruiting
Good: no order effects I controls important CV
-will not guess aim – so behaviour is more natural
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 other to B.
Problems: matching is time consuming, not perfect and can’t control all relevant variables – may not address participant variables.
- more participants more time and expense
Good: Participants matched on a variable relevant to experiment – enhances validity
- No order effects, only tested once so no fatigue or practise – enhances validity
- A small scale trial run of a research design eg experiment or interview before doing the actual investigation
-it is done in order to find out if certain aspects of the design don’t work out and make adjustments, saving time and money.
Confederate – sometimes a researcher has to use another person to play a role in an experiment. Eg if you want to find out if people respond differently to orders from someone wearing a suit. This is a confederate.
what is a true experiment
– more control, less realistic
- Conducted in a controlled environment where extraneous and confounding variables can be controlled ( doesn’t have to be a lab could be a classroom)
When the IV is under direct control of the researcher who manipulates it and records effect on the DV eg only Lab and Field
strengths and weaknesses of Laboratory Experiments
+ EV’s and CV’s can be controlled so the effect on the DV can be minimised and cause and effect between the IV and DV can be demonstrated (high internal validity)
+ can be easily replicated due to standardised procedure. If the results are the same this confirms validity
- may lack generalisability. This controlled lab environment may be artificial and participants are aware they are being tested Thus, behaviour may not be ‘natural’
- demand characteristics may be a problem These are clues in the experimental situation that invite a particular response from participants. The results of the experiment may be explained by these clues rather than the effect of the IV and get participants to act in a certain way
less control, more realistic
- The Iv is manipulated in natural more everyday setting in the field ( not necessarily an actual field
Positives and negatives of a field experiment
+ more natural environment. Participants more comfortable in their own environment Results may be more generalisable
+Participants are unaware of being studied They are most likely to behave as they normally do so the findings can be generalised. The study has greater external validity
- More difficult to control CV’s. Observed changes in the DV may not be due to the IV, but to CVs instead. It is more difficult to establish cause and effect than in a lab
- - There are ethical issues Participants in a field experiment may not have given informed consent. invasion of privacy.
The experimenter takes advantage of the pre-existing IV’s. The IV would have varied even if the experimenter wasn’t interested.
Positives and negatives of a natural experiment
+ May be the only ethical option It may be unethical to manipulate the IV. Eg studying the effects of institutionalisation of children A natural experiment may be the only way causal research can be done for such topics.
+ greater external validity. Natural experiments involve real-life issues such as the effect of a natural disaster on stress levels. This means the findings are more relevant to real experiences
- the natural event may only occur rarely. Many natural events are ‘one off’ incidents and this reduces the opportunity for research .This may limit the scope for generalising findings to other similar situations.
- participants are not randomly allocated The experimenter has no control over which participants are placed in which condition as the IV is pre-existing. May result in CV that aren’t controlled, e.g Romanian orphans adopted early may also be the friendlier ones.