key science skills Flashcards
Independent variable
variable being manipulated
Dependent variable
variable being tested
Confounding variables
unwanted variables that HAVE affected the DV. EVs that weren’t controlled.
Extraneous variables
unwanted variables that MAY affect the DV.
Controlled variables
a variable held constant to ensure that the only influence on the DV is the IV
Random sampling
ensures every member of the population has an equal chance of being selected to be part of the sample
Advantages of random sampling
representative population
disadvantages of random sampling
- time consuming
- need a complete list of the target audience
stratified sampling
a sampling technique involving sampling from different subgroups in the same proportions as they occur in the population of interest
advantages of stratified sampling
- enables the researcher to sample specific groups for comparison purposes
- high representativeness
disadvantages of stratified sampling
- time consuming
- needs a complete list of the population
experimental group
the group that undergoes the experimental condition/s
control group
the group that doesn’t undergo the experimental condition/s and is used as a baseline
within subjects design
each participant is in both the experimental and control groups/all conditions
between subjects design
each participant is assigned to only one group or condition and provides only one score
mixed design
an experimental design that combines the features of the within subject and between subjects designs
advantages of within subject groups
- better at controlling participant variables
- small sample required
disadvantages of within subject groups
- doesnt necessarily control all variables
- participant dropout rate
advantages of between subject groups
- low participant dropout rate
- can be done on one occasion
disadvantages of between subject groups
- large number of participants needed
- less control over participant variables
advantages of mixed design
- has strengths of within subjects and between subjects
- fewer participants are needed
- more precise results
disadvantages of mixed design
time consuming
participant variables
personal characteristics of a research participant that could influence their responses
situational variables
external factors associated with the experimental setting that may influence responses
demand characteristics
cues in an experiment that may influence or bias a participant’s response
experimenter effects
any influence on the results produced by the person carrying out the research
placebo effects
when there is a change in a participant’s behaviour due to their belief that they are receiving an experimental treatment and they respond according to this rather than to the effect of the independent variable
order effects
when performance on the dependent variable is influenced by the specific order of an experiment rather than the independent variable
single blind procedure
a procedure in which participants are unaware of the experimental condition they are in
double blind procedure
a procedure where both the participants and the experimenter are unaware of the conditions allocated to participants
systematic errors
errors in data that differ from the true value by a consistent amount
random errors
errors in data that are unsystematic and occur due to chance
personal errors
include mistakes, miscalculations, and observer errors when conducting research
repeatability
the degree to which a specific research investigation obtains similar results when it’s conducted again under the same conditions every time
reproducibility
how close the results are to each other when an investigation is replicated under changed conditions
validity
the extent to which psychological investigations truly support their findings
internal validity
the extent to which an investigation truly measures or investigates what it claims to do
external validity
the extent to which the results of an investigation can be applied to similar individuals in different settings
Accuracy
How close it is to the true value of the quantity being measured
Precision
How closely a set of measurement values agree with each other
