Research methods Flashcards
what is hypothesis
a statement predicting what research results will show before it is carried out
the two types of hypothesis
alternative hypothesis
null hypothesis
what is alternate hypothesis
a statement that predicts a difference or correlation in results
what is null hypothesis
a statement that predicts no difference or correlation in results
what is independent variable
something the researcher changes or manipulates
what is dependent variable
something that is measured to see if it has changed (after an independent variable has been manipulated)
why don’t researchers use IV and DV when predicting a correlation
correlations do not show cause and effect, they instead measure two co-variables to see if there is a relationship between them
what is cause and effect
the process of one variable affecting a change in another
what is co-variable
something that changes in relation to another variable
why is the best method to establish if one variable affects another is to do an experiment
experiments allow psychologists to have control over extraneous variables
what is extraneous variable
a variable, apart from the independent variable, that can affect the dependent variable unless it’s controlled
what is a common way to control extraneous variables
keeping them the same across conditions, known as standardisation
what is standardisation
a way of controlling extraneous variables that keeps them the same across conditions
what is experimental design
the way participants are allocated to conditions in an experiment
two methods of experimental design
repeated measures design
independent measures design
what is repeated measures design
an experimental design where participants take part in each condition
what is independent measures design
an experimental design where participants are different in each condition
strength of repeated measures
comparing ‘like with like’ so differences are not due to individual differences between participants
fewer participants need to be recruited, saving money and time
weakness of repeated measures design 1
participants may perform worse on the second condition due to the boredom or fatigue effect
weakness of repeated measures design 2
participants may perform better on the second condition due to the practice effect
weakness of repeated measures design 3
participants may work out the independent variable and change their behaviour accordingly (the effect of demand characteristics)
weakness of repeated measures design 4
the task may need to be changed between conditions, making it an extraneous variable
strength of independent measures design 1
no order effects (boredom/fatigue effect, practice effect, demand characteristics)
what are order effects
factors that impact negatively on research findings because participants follow the same order of conditions in an experiment
strength of independent measures design 2
the same task can be used in both conditions because participants will not be familiar with it
weakness of independent measures design 1
differences between conditions could be due to participant variables
weakness of independent measures design 2
potentially, more participants need to be recruited as they cannot be used more than once per condition
what is sample
a group selected from a larger population
what is target population
the entire set of people psychologists want to research
what is representative
an accurate reflection of a larger group
what is generalisability
the ability to draw conclusions that apply to a larger group outside of research
what is random sample
a sample selected using chance
what is opportunity sample
a sample selected by convenience
what is self-selected sample
a sample selected through volunteers
what is sampling method
a technique for selecting participants from a population
strength of opportunity sampling
it is quick and convenient compared to random sampling
weakness of opportunity sampling
it is biased as studying people who are available as they live close by may result in a group of similar people, in terms of age, education, ethic group or social class
strength of self-selected sampling
psychologists do not have to put much effort into selecting participants as they volunteer themselves, they also have consent from the participants
what is consent
when a person agrees on being studied or agrees on someone’s behalf
weakness of self-selected sampling
certain types of people are more likely to volunteer to take part in psychological research and they will be over-represented in the sample
strength of random sampling
it is very likely to give a representative sample, there is no bias
weakness of random sampling
there is a chance of a freak sample where certain types of people are over-represented and others are under-represented or missing from the sample
