INVESTIGATION DESIGN, DATA ANALYSIS AND PRESENTATION

Question 1

Hypothesis

Answer 1

A statement that is testable

Null and alternative hypothesis are proposed. Based on findings, the researcher decides whether it is more plausible to accept or reject each hypothesis.
–> if variations were unlikely to be by chance, null is rejected

Question 2

Alternative hypothesis (H1)

Answer 2

(Also called the experimental hypothesis) predicts that something other than a chance variation alone has played a part in producing the results obtained
-Can be directional/one tailed or non directional/two tailed

Question 3

Directional/one tailed hypothesis

Answer 3

Predicts the direction in which results are expected to occur

For example: those who eat chocolate will become fatter than those who eat fruit

Question 4

Non-directional/two tailed hypothesis

Answer 4

Does not predict the expected direction of the outcome, only that there will be a difference caused by a variable

Question 5

Null hypothesis (H0)

Answer 5

Predicts that the results of an experiment can be explained by chance variation alone rather than by the manipulation of the IV. Predicts that the alternative hypothesis is untrue

Question 6

Independent groups design

Answer 6

Different participants are used in each condition of the experiment. Experiments using this condition usually have a control/experimental condition OR two+ experimental conditions

Participants are randomly allocated to ensure that participant variables do not differ systematically between the groups, or individual differences relevant to the experiment may confound results. Done with randomizer

Question 7

Repeated measures design

Answer 7

Exposes every participant to all conditions of the experiment

Order effects can be minimised by counterbalancing or ranomization

(i) counterbalancing: equal number of participants completing tasks in different orders
(ii) Randomly determining the presentation of the experimental conditions

Question 8

Matched pairs design

Answer 8

Middle way between independent groups/Repeat measures designs. Match participants in one condition as closely as possible with one in the other on all variables considered relative to performance in the study

Question 9

Evaluation of independent groups design

Answer 9

Advantages: No order effect issues creating positive or negative performance in the task. Through repetition, boredom or fatigue

Disadvantages: Chance that individual differences would contaminate results. Uneconomical as 2* as many participants required

Question 10

Evaluation of repeated measures design

Answer 10

Advantages: Individual differences removed as a confounding variable. Fewer participants required

Disadvantages: Risk of order effects as both participants exposed to both conditions in sequence. Further limited use, as in some cases it would be inappropriate to expose participants to two conditions

Question 11

Evaluation of matched pairs design

Answer 11

Advantages: Combines benefits of independent groups/repeated measures designs

Disadvantages: costly, difficult and time consuming. Hard to match people up exactly.

Question 12

Pilot study

Answer 12

Small scale trial run of a specific research investigation to test the procedure and highlight any potential issues. Identifies problems with design, instructions and measurement of the DV

Question 13

Examples of random errors (cant be predicted)

Answer 13

• pps state of mind
• pps level of motivation
• incidental noise
• room temperature
• previous experiences of the pps on the day of the study

Question 14

Random sampling

Answer 14

Every person in the target population has equal chance of being selected for the study. Must be completely random selection (ie random number generator) but cannot guarantee representative sample

Question 15

Opportunity sampling

Answer 15

Researcher selects anyone available to participate in the study. Convenient but may not be representative

Question 16

Volunteer sampling

Answer 16

Participants select themselves to take part in the study, walk in or after replying to advert. Hard to get responses and may not represent target population as a certain type of person (ie enthusiastic) will respond more readily than others in the population sample

Question 17

Examples of demand characteristics (people try to make sense of the research situation they are in and act accordingly)

Answer 17

• Guessing the hypothesis and acting to appease it or derail it
• Act nervously/out of character, ie feeling evaluated and therefore nervous
• Displaying social desirability bias, wanting others to see the person in the most favorable light

Question 18

Investigator effects

Answer 18

-Effect of the researcher’s own behavior and characteristics on the investigation. Bias observing due to wanting a particular outcome, altering results. Presence of observer in group may cause bias in naturalistic observation, and communication style may have an effect in interviews

Question 19

Median

Answer 19

middle value of scores arranged in descending or ascending order. Unaffected by outlying values, safe measure of central tendency but affected by alterations to central values in a data set and not effective with small values

Question 20

Mean

Answer 20

Arithmetic average. Powerful measure of central tendency as uses all data, but affected by anomalies in the data

Question 21

Mode

Answer 21

Most frequently occurring value. Easy to identify, however when small data sets are compared, even tiny changes massively alter mode

eg: 3356838 vs 3356878. 3 vs 8 (?)

Question 22

Standard deviation

Answer 22

Measure of the variability of the data from its mean