KEY SKILLS WEEK 4

Question 1

what is a variable?

Answer 1

• a characteristic that can assume multiple values or can vary e.g. age,weight, alcohol consumption
• also used to describe an event or condition which a researcher observes or measures
• must be operational i.e. explicitly stated and able to be measured

Question 2

what are constructs?

Answer 2

-defined by theoretical definitions e.g. intelligence: the capacity to acquire and apply knowledge faculty of thought and reason

Question 3

what is an Independent variable (IV)?

Answer 3

• the variable that is manipulated or in some other way is hypothesised to bring out the change in the dependant variable

Question 4

what is an Dependant variable? (DV)

Answer 4

• the variable upon which the study depends. usually variable which is measured.

Question 5

what are the two types of independent variables?

Answer 5

• quasi independent - e.g gender, age,group,smoking status ; characteristics that cannot be randomly assigned
• true independent variables- e.g. drug treatments ,counselling- you can randomly assign people to groups

Question 6

Identify the different types of scales of measurements?

Answer 6

• nominal: data is nto numerical and items are named or put in categories
• ordinal: data can be organized into ranks and distance between ranks is not known
• interval : data contains equal intervals and has no true zero e.g. temp and IQ
• ratio - data which does all the above and has a true zero point - height ,distance and age

Question 7

Define reliability?

Answer 7

• whether an instrument can be interpreted consistently across different situations

Question 8

what are different forms of reliability?

Answer 8

• test- retest reliability ; measures fluctuations from one time to another
• Alternate forms reliability - give different versions of the same test to the group on different occasions
• inter-rater reliability - measures fluctuations between observers

Question 9

Define validity

Answer 9

-whether an instrument measures what it set out to measure

Question 10

what are the different forms of validity?

Answer 10

• Face validity- Does it look like a good test
• Criterion Validity- does the measure give results which are in agreement with other measures
• concurrent- comparison of new test with established test
• predictive - when data from a new instrument are used to predict future observations
• construct validity-how does the test tap into the underlying construct
• ecological validity - study reflect natural occurring behaviour
  population behaviour - is our sample adequate