correlations

Question 1

what do correlations measure

Answer 1

-relationship and association between the two co variables
-plotted on scatter gram
-analysed using statistical tests

Question 2

what numerical values do correlations produce

Answer 2

• (-1 and +1) known as correlation co efficient

Question 3

what does correlation cofficient tell you

Answer 3

-tell us the strength and direction of the RS between two variables

Question 4

what do different co efficents mean

Answer 4

-+1 is perfect positive correlation
-(-1) is a perfect negative correlation
-the closer to +1 or -1 the stronger the RS between the 2 co varibales
-the closer to 0 the weaker

Question 5

what should you be careful about?

Answer 5

note that coffeciates that indicate a weak correlation may be significant still depending on size of data set

Question 6

visualize the diagrams in revision folder

Question 7

what is a positive correlation?

Answer 7

-as on variable increases so does the other
-e.g no. of ppl and amount of noise

Question 8

what is negative correlation?

Answer 8

-as co var increases, the other decreases
-e.g ppl in room vs amount of personal space

Question 9

what is zero correlation

Answer 9

-when theres no RS between the co variables e.g number of ppl in a room and amount of rainfall in peru

Question 10

what are some correlational hypothesis

Answer 10

-the more caffiene the less sleep (NC and directional)
-the more caffiene the more energy(PC and directional)
-caffiene has no effect on the amount of times someone sees a cat cross the road(zero C and null)

Question 11

what are the strengths

Answer 11

-you may not always be able to manipulate varibales so you may want to study naturally occuring events

-reliability can be tested (stays the same if tested gaain) as its quantitative

-it may show a RS between 2 var as it suggests how they might affect eachother so useful for future studied to look at cause for RS of 2 variables

Question 12

what are the weaknesses

Answer 12

• reducing rich, qualitative data to numerical vlaues reducing valdiity (wider insight lost)

-lack valdiity 2 vars must be operationalised and could result from real life data e.g hard to operationalise persons anxiety of injections

-shows RS but not cause we dont know for sure that the tv is causing violent behvaiour other factors not taken into account

Question 13

what may the RS between scores on maths and music test show

Answer 13

-negative correlation
-e.g the higher in maths the lower in music
-may be some outliers so makes correlation weak(closer to 0)
-if its a small sample it can limit conclusions that can be drawn out