RESEARCH METHODS EXAM
QUESTIONS, ANSWERS & MARKS What is an experiment? - Correct Answer 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 - Correct Answer 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)? - Correct Answer 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)? - Correct Answer 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? - Correct Answer 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? - Correct Answer 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? - Correct Answer 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) 1 / 2
Distinguish between independent groups, matched pairs and repeated measures designs - Correct Answer 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? - Correct Answer 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? - Correct Answer 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? - Correct Answer 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? - Correct Answer 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:
- Correct Answer The population / mean for imagery scores is higher than the /
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population / mean for repetition scores. (4 marks) Provide a null hypothesis to go with it - Correct Answer 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? - Correct Answer 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)