research methods: variables and hypotheses

Question 1

what is the iv?

Answer 1

• the independent variable is changed or manipulated by researcher
• this is to see the effect on the dependent variable

Question 2

what is the dv?

Answer 2

• the dependent variable is measured by the researcher
• it changes as a result of the manipulation of the iv

Question 3

what is required for both iv and dv?

Answer 3

• they have to both be measureable
• to do this, they need to be operationalised (defining precisely how you intend to measure the dv and alter the conditions of the dv**

Question 4

what variables does the experimenter control?

Answer 4

• the iv - making it change to see what happens
• experimenter also has to control other variables - extraneous variables - to make sure that they do not change - other wide they may spoil the experiment

Question 5

what is an extraneous variable?

Answer 5

• variable that may have affected the dependent variable but that was not the independent variable

Question 6

what is a confounding variable?

Answer 6

• variable that affects findings of a study directly, so much that you are no longer ,ensuring what was intended
• so an extraneous variable can become a confounding variable

Question 7

what can extraneous and confounding variables be divided into?

Answer 7

• situational variables
• participant variables

Question 8

what is a situational variable?

Answer 8

• an extraneous variable that may affect results of a study could be found in the environment in which the study is conducted
• factors such as noise, time of day, temperature, disturbances etc may affect results of study so should be controlled or dominated
• controlling extraneous variables means that they are held constant for all ppts so variable affects everyone equally
• eliminating extraneous variables involves removing possibility of them occurring in the first place

Question 9

what is a participant variable?

Answer 9

• ppts themselves may affect results of study as they have different characteristics e.g. intelligence, level of motivation, age, personality, skills

Question 10

what are the problems with situational and participant variables?

Answer 10

• very difficult to control for all situational and participant variables, probably impossible
• only necessary to control for variables that might have unwanted impact on dv

Question 11

what should be considered?

Answer 11

• nature and aims of an investigation before deciding which extraneous variables are likely to have effect - and therefore which ones need to be controlled prior to undertaking the study

Question 12

what is a hypotheses?

Answer 12

• a specific testable prediction

Question 13

what is the experimental hypothesis?

Answer 13

• generated
• statement of what is expected
• experimental hypothesis is the alternative hypothesis (alternative to null hypothesis)

Question 14

what is the null hypothesis?

Answer 14

• states that any difference or relationship is due to chance
• no relationship or difference as predicted
• tested when using statistical testing

Question 15

what is directional hypothesis?

Answer 15

• one-tailed
• states direction of hypothesis (can be predicted)

Question 16

what is non-directional hypothesis?

Answer 16

• two-tailed
• just states that there is a difference