⭐ • Research Methods: Standard Deviation

Question 1

What is the standard deviation?

Answer 1

How far scores deviate/ are spread out from from the mean

Question 2

What is the advantage to a standard deviation?

Answer 2

It’s a precise measure of the dispursion of data as all the exact values are taken into account when calculating

Question 3

What is the disadvantage to a standard deviation?

Answer 3

It may hide some of the characteristics of the data set e.g. extreme values (anomalies) cannot be immediately sensed from data

Question 4

Why is small standard deviation desirable?

Answer 4

• A small standard deviation is desirable as it infers that all the results were close to the average, meanining there are little to no anomalous results (ones further away from mean)
• In medical sense, small SD means that drug’s effect works as intended with a loq percentage of unexpected side effects (anomalies)

Question 5

Under what ‘group’ does standard deviation come under in Quantitative data analysis?

Answer 5

Measures of Dispersion

Question 6

Complete this labelled diagram of the formula for standard deivation

Answer 6

Question 7

When squaring x - x̄ what do you do if the answer is a negative number and why?

Answer 7

• If the answer is negative then you can simply ignore it/ remove the negative as when squared negative numbers become positive
• In the sense of the actual formula, when it comes to adding up all the answers to x - x̄ due to ∑ (the formula requiring to sum them) it doesnt give the correct answer, all in that column should be positive as they have all been squared

Question 8

Why is it best to write all your workings out and what is the best way to lay out workings?

Answer 8

• You will get marks for your clear method of workings out if your final answer is wrong
• It is best to complete formula one step at a time, logically, subbing in the numbers as you go along to be clear to yourself as you work out standard deviation and to be clear for examiner

Question 9

Why is it important to read the question carefully?

Answer 9

As some questions may ask for your final answer to 1 d.p. or 2 d.p.

Question 10

What is the best way to set up answering a standard deviation question?

Answer 10

To draw a table next to raw scores with two columns, one for the answer to x - x̄ and one for that answer squared so its then easy to total the final scores (e.g. as shown in image)