AQA A Level Psychology Research
Methods (Latest 2025/ 2026 Update)
Questions and 100% Correct Verified
Answers [Grade A] – University of
California, Berkeley
Outline what investigator effects are and the three main types -correct answer This
results from the effects of the researchers behaviour on an investigation causing
participants to act differently
Experimenter Bias
Every researcher has an expectation of what they expect to find and thus they may
unconsciously influence the situation via body language/facial expressions
Observer Bias
Just the presence of an observer being there can cause participants to behave in a
different manner to normal
Interviewer Bias
When carrying out an interview the presence of the interviewer may influence the
participants response
Outline and evaluate the three experimental designs -correct answer Independent
Measures Design
, AQA A Level Psychology Research
Methods (Latest 2025/ 2026 Update)
Questions and 100% Correct Verified
Answers [Grade A] – University of
California, Berkeley
This is where different participants take part in each condition of the IV ie. one group
drinks redbull one group doesn't
:) - There will be no order effects
:) - It can be used when repeated measures design is inappropriate
:( - Errors may occur due to the individual differences not being controlled which
could then act as confounding variables and ruin the results gained, reducing internal
validity
:( - You need more participants unlike repeated measures
Repeated Measures Design
In this design every participant will take part in every condition of the IV
:) - Individual differences between participants are removed as potential confounding
variables
:) - Requires fewer participants
:( - Order effects may results in the participants becoming bored or better after the
first IV
:( - Participants are more likely to guess the purpose of the study, picking up on clues
from the researcher and thus changing their natural behaviour
, AQA A Level Psychology Research
Methods (Latest 2025/ 2026 Update)
Questions and 100% Correct Verified
Answers [Grade A] – University of
California, Berkeley
Matched Pairs Design
Matching each participant in one of the experimental conditions as closely as
possible with another participant in the second condition ie. age/gender/IQ
:) - Controls the individual differences of participants unlike in an independent
measures design
:) - There is no order effects as the participants will only be in one condition
:( - Very time consuming to find a large sample and then match every single one with
someone else with similar characteristics
Outline what method is used to control for individual differences in an independent
measures design -correct answer Random allocation can be used where participants
are randomly assigned into different groups
Outline what method is used to combat order effects in a repeated measures design -
correct answer Counterbalancing is used whereby the participants are split in half
where half A will do condition 1 and then 2 and half B will do condition 2 and then 1.
Methods (Latest 2025/ 2026 Update)
Questions and 100% Correct Verified
Answers [Grade A] – University of
California, Berkeley
Outline what investigator effects are and the three main types -correct answer This
results from the effects of the researchers behaviour on an investigation causing
participants to act differently
Experimenter Bias
Every researcher has an expectation of what they expect to find and thus they may
unconsciously influence the situation via body language/facial expressions
Observer Bias
Just the presence of an observer being there can cause participants to behave in a
different manner to normal
Interviewer Bias
When carrying out an interview the presence of the interviewer may influence the
participants response
Outline and evaluate the three experimental designs -correct answer Independent
Measures Design
, AQA A Level Psychology Research
Methods (Latest 2025/ 2026 Update)
Questions and 100% Correct Verified
Answers [Grade A] – University of
California, Berkeley
This is where different participants take part in each condition of the IV ie. one group
drinks redbull one group doesn't
:) - There will be no order effects
:) - It can be used when repeated measures design is inappropriate
:( - Errors may occur due to the individual differences not being controlled which
could then act as confounding variables and ruin the results gained, reducing internal
validity
:( - You need more participants unlike repeated measures
Repeated Measures Design
In this design every participant will take part in every condition of the IV
:) - Individual differences between participants are removed as potential confounding
variables
:) - Requires fewer participants
:( - Order effects may results in the participants becoming bored or better after the
first IV
:( - Participants are more likely to guess the purpose of the study, picking up on clues
from the researcher and thus changing their natural behaviour
, AQA A Level Psychology Research
Methods (Latest 2025/ 2026 Update)
Questions and 100% Correct Verified
Answers [Grade A] – University of
California, Berkeley
Matched Pairs Design
Matching each participant in one of the experimental conditions as closely as
possible with another participant in the second condition ie. age/gender/IQ
:) - Controls the individual differences of participants unlike in an independent
measures design
:) - There is no order effects as the participants will only be in one condition
:( - Very time consuming to find a large sample and then match every single one with
someone else with similar characteristics
Outline what method is used to control for individual differences in an independent
measures design -correct answer Random allocation can be used where participants
are randomly assigned into different groups
Outline what method is used to combat order effects in a repeated measures design -
correct answer Counterbalancing is used whereby the participants are split in half
where half A will do condition 1 and then 2 and half B will do condition 2 and then 1.
