RESEARCH METHODS EXAM
QUESTIONS, ANSWERS & MARKS
What is an experiment?
An experiment is a research technique in which an IV is manipulated / and the effects of
this on a DV are observed and measured. / Other (extraneous) variables are held
constant. / A true experiment is one in which the IV is directly under the experimenter's
control (as in laboratory or field experiments). / In natural and quasi-experiments the IV
varies on its own and some would argue that, because of this, they are not really
experiments. (5 marks)
Identify one difference between an experiment and a correlation
The main difference between an experiment and a correlation is that experiments
enable us to talk about 'cause and effect' / whereas correlations simply describe
patterns of linear relationship between pairs of data / and do not allow us to make cause
and effect statements. / In addition, an experiment is a research method / but correlation
is a technique of data analysis applied to data gathered by some other means. (5
marks)
What is an independent variable (IV)?
An IV is the influencing factor / which a researcher manipulates in an experiment / in
order to observe its effect on a DV / for example, in a study of the effect of alcohol on
driving ability, the IV would be the amount of alcohol given to the drivers. (4 marks)
What is a dependent variable (DV)?
A DV is the factor in an experiment which is influenced by changes in the IV / and which
is observed and measured by the researcher. / In the example given in 3, the DV would
be driving ability. (3 marks)
What is a confounding variable?
A confounding variable is an influence in an experiment that is not the IV yet causes
changes in the DV. / For example, researchers may find age affects IQ in that older
people do less well than younger people. / However, this could be due to the
confounding variable of how the test is approached. Older people may be more careful
and less concerned about 'beating the clock' than are younger people, consequently,
their scores are lower. (3 marks)
What is an extraneous variable?
Extraneous variables are all other variables apart from the IV and DV that need to be
controlled in an experiment / e.g. the testing environment, time of day, instructions to
participants. / If extraneous variables are not taken care of they could obscure the effect
of the IV / or, if systematic, turn into a confounding variable. (4 marks)
What is a control group?
In a simple two-sample experiment, control group participants are affected by
everything the experimental group experiences with the exception of the IV. / Scores
from the control group thus provide baseline data / against which scores from the
experimental group can be compared. (3 marks)
, Distinguish between independent groups, matched pairs and repeated measures
designs
These are experimental designs / used to control variation due to individual differences
between participants. / In a simple experiment comparing two conditions, the
independent groups design consists of two different groups of participants / who have
been allocated by chance to either of the two conditions. / Matched pairs designs
involve pairing participants on variables relevant to the study / then splitting the pairs
and randomly allocating the members of the pair to one or other condition. / In a
repeated measures design, participants undergo both conditions in the experiment. (7
marks)
What are practice effects?
Practice effects occur in repeated measures designs / when participants carry over an
improvement to the second experimental condition / as a result of having done the first
condition. / (In this case, practice becomes a confounding variable.) (4 marks)
What are order effects?
Order effects occur in repeated measures designs / when participants' performance in
the second condition is affected by them having done the first. / This could include
improvements, as in practice effects, / but it also includes the detrimental effects of
fatigue or boredom. (4 marks)
What is counterbalancing?
Counterbalancing is routinely built into repeated measures designs / as a precaution
against order or practice effects. / Half the participants do condition A first followed by B,
and half do B first followed by A, / hence the term ABBA design. (4 marks)
What is randomisation?
Randomisation can refer to the random allocation of participants to conditions to help
control for variation due to participants. / Secondly, it can refer to randomising the order
in which participants take part in conditions (thus achieving a similar effect to
counterbalancing). / Thirdly, it can refer to randomising the order of stimulus materials
for each participant e.g. a word list in a memory experiment might be given on a
different order to each participant. (3 marks)
Write out a hypothesis for a study comparing imagery and repetition as aids to
memory:
The population / mean for imagery scores is higher than the / population / mean for
repetition scores. (4 marks)
Provide a null hypothesis to go with it
The difference between the / population / means for imagery and repetition is zero. (3
marks)
What is a directional hypothesis and when would it be used?
A directional hypothesis predicts the direction in which results will fall / e.g. the
population mean of sample A is higher than the mean of sample B / or the correlation
between C and D is positive. / Such hypotheses are used only when we have good
reason to predict the direction of the results / e.g. when previous research or careful
reasoning suggest it. (5 marks)
What is a non-directional hypothesis and when would it be used?
A non-directional hypothesis does not predict the direction in which results will fall / e.g.
the population means of sample A and sample B differ / or there is a correlation
QUESTIONS, ANSWERS & MARKS
What is an experiment?
An experiment is a research technique in which an IV is manipulated / and the effects of
this on a DV are observed and measured. / Other (extraneous) variables are held
constant. / A true experiment is one in which the IV is directly under the experimenter's
control (as in laboratory or field experiments). / In natural and quasi-experiments the IV
varies on its own and some would argue that, because of this, they are not really
experiments. (5 marks)
Identify one difference between an experiment and a correlation
The main difference between an experiment and a correlation is that experiments
enable us to talk about 'cause and effect' / whereas correlations simply describe
patterns of linear relationship between pairs of data / and do not allow us to make cause
and effect statements. / In addition, an experiment is a research method / but correlation
is a technique of data analysis applied to data gathered by some other means. (5
marks)
What is an independent variable (IV)?
An IV is the influencing factor / which a researcher manipulates in an experiment / in
order to observe its effect on a DV / for example, in a study of the effect of alcohol on
driving ability, the IV would be the amount of alcohol given to the drivers. (4 marks)
What is a dependent variable (DV)?
A DV is the factor in an experiment which is influenced by changes in the IV / and which
is observed and measured by the researcher. / In the example given in 3, the DV would
be driving ability. (3 marks)
What is a confounding variable?
A confounding variable is an influence in an experiment that is not the IV yet causes
changes in the DV. / For example, researchers may find age affects IQ in that older
people do less well than younger people. / However, this could be due to the
confounding variable of how the test is approached. Older people may be more careful
and less concerned about 'beating the clock' than are younger people, consequently,
their scores are lower. (3 marks)
What is an extraneous variable?
Extraneous variables are all other variables apart from the IV and DV that need to be
controlled in an experiment / e.g. the testing environment, time of day, instructions to
participants. / If extraneous variables are not taken care of they could obscure the effect
of the IV / or, if systematic, turn into a confounding variable. (4 marks)
What is a control group?
In a simple two-sample experiment, control group participants are affected by
everything the experimental group experiences with the exception of the IV. / Scores
from the control group thus provide baseline data / against which scores from the
experimental group can be compared. (3 marks)
, Distinguish between independent groups, matched pairs and repeated measures
designs
These are experimental designs / used to control variation due to individual differences
between participants. / In a simple experiment comparing two conditions, the
independent groups design consists of two different groups of participants / who have
been allocated by chance to either of the two conditions. / Matched pairs designs
involve pairing participants on variables relevant to the study / then splitting the pairs
and randomly allocating the members of the pair to one or other condition. / In a
repeated measures design, participants undergo both conditions in the experiment. (7
marks)
What are practice effects?
Practice effects occur in repeated measures designs / when participants carry over an
improvement to the second experimental condition / as a result of having done the first
condition. / (In this case, practice becomes a confounding variable.) (4 marks)
What are order effects?
Order effects occur in repeated measures designs / when participants' performance in
the second condition is affected by them having done the first. / This could include
improvements, as in practice effects, / but it also includes the detrimental effects of
fatigue or boredom. (4 marks)
What is counterbalancing?
Counterbalancing is routinely built into repeated measures designs / as a precaution
against order or practice effects. / Half the participants do condition A first followed by B,
and half do B first followed by A, / hence the term ABBA design. (4 marks)
What is randomisation?
Randomisation can refer to the random allocation of participants to conditions to help
control for variation due to participants. / Secondly, it can refer to randomising the order
in which participants take part in conditions (thus achieving a similar effect to
counterbalancing). / Thirdly, it can refer to randomising the order of stimulus materials
for each participant e.g. a word list in a memory experiment might be given on a
different order to each participant. (3 marks)
Write out a hypothesis for a study comparing imagery and repetition as aids to
memory:
The population / mean for imagery scores is higher than the / population / mean for
repetition scores. (4 marks)
Provide a null hypothesis to go with it
The difference between the / population / means for imagery and repetition is zero. (3
marks)
What is a directional hypothesis and when would it be used?
A directional hypothesis predicts the direction in which results will fall / e.g. the
population mean of sample A is higher than the mean of sample B / or the correlation
between C and D is positive. / Such hypotheses are used only when we have good
reason to predict the direction of the results / e.g. when previous research or careful
reasoning suggest it. (5 marks)
What is a non-directional hypothesis and when would it be used?
A non-directional hypothesis does not predict the direction in which results will fall / e.g.
the population means of sample A and sample B differ / or there is a correlation
