Graphs & Distributions

Question 1

● What is meant by a distribution?

Answer 1

The spread of a data set showing possible values and how frequently each occurs

Question 2

● What does a normal distribution curve look like?

Answer 2

Symmetrical curve

Question 3

● Where do the mean, median, and mode lie in a normal distribution?

Answer 3

Around the same midpoint on the curve

Question 4

● What is a positive skew?

Answer 4

Most data on the left, long tail on the right

Question 5

● What is a negative skew?

Answer 5

Most data on the right, long tail on the left

Question 6

● Which type of graph would you use to display frequencies of scores in categories?

Answer 6

Bar chart

Question 7

● Which type of graph would you use to display frequencies of continuous data?

Answer 7

Histogram

Question 8

● Which type of graph displays the relationship between two co-variables?

Answer 8

Scattergraph

Question 9

● What does discrete data mean?

Answer 9

Data can be categorised into groups

Question 10

● What does continuous data mean?

Answer 10

Data measured using scientific tools, e.g. height, weight, time

Question 11

● On a bar chart, should the bars touch each other?

Answer 11

No

Question 12

● On a histogram, should the bars touch each other?

Answer 12

Yes

Question 13

● What should you always plot first when drawing a distribution curve?

Answer 13

The mode

Question 14

● What does each plot represent in a scattergraph?

Answer 14

One participant but two scores

Question 15

● What do you plot on the y-axis of a bar chart?

Answer 15

Amount (e.g. mean number) of each category

Question 16

● What type of data is plotted on the horizontal axis of a histogram?

Answer 16

Scores made up of equal sized intervals

Question 17

● What is a correlation coefficient?

Answer 17

A value indicating the strength and direction of a relationship

Question 18

● What does a correlation coefficient of +0.7 indicate?

Answer 18

Strong positive correlation

Question 19

● What does a correlation coefficient of -0.7 indicate?

Answer 19

Strong negative correlation

Question 20

● What value indicates no correlation?

Answer 20

0

Question 21

● Which type of data does a histogram represent?

Answer 21

Continuous data or individual scores for each participant

Question 22

▲ Why is it important to label the axis operationally on a graph?

Answer 22

To clearly show what is being measured

Question 23

▲ Why are bars in a bar chart not touching?

Answer 23

To show separate conditions (discrete data)

Question 24

▲ Why should you use a bar chart for mean values from two groups?

Answer 24

Because the conditions are categories

Question 25

▲ When would you use a histogram instead of a bar chart?

Answer 25

When data is continuous or frequencies for intervals

Question 26

▲ Why would you use a scattergraph?

Answer 26

To show the relationship between two co-variables

Question 27

▲ If a test is very easy, what skew is likely?

Answer 27

Negative skew

Question 28

▲ If a test is very hard, what skew is likely?

Answer 28

Positive skew

Question 29

▲ Why might a researcher use a frequency table before drawing a histogram?

Answer 29

To group scores into intervals for plotting

Question 30

▲ What does a strong positive correlation mean in terms of data points?

Answer 30

As one variable increases, so does the other

Question 31

▲ What does a strong negative correlation mean?

Answer 31

As one variable increases, the other decreases

Question 32

▲ Why do you plot the mode first when drawing a normal distribution?

Answer 32

It shows where most of the distribution will be

Question 33

▲ What is the purpose of using a bar chart in psychological research?

Answer 33

To compare conditions with categorical data

Question 34

✪ Explain how to choose between a bar chart and histogram for psychological data.

Answer 34

Bar charts: Used to display DISCRETE/CATEGORICAL data. Used when data is divided into categories. Histograms: Used to display CONTINUOUS data or data where each participant has an individual score.

Question 35

✪ Critically discuss the purpose of a scattergraph in psychological research

Answer 35

Scattergraph: Used to display a RELATIONSHIP between two co-variables. Each plot on the graph represents ONE ppt but TWO scores (one score from each co-variable).

Question 36

✪ Explain what discrete and continuous data are and how they are represented graphically.

Answer 36

Discrete Data – Information/findings that can be categorised into groups, the data can only appear in one category. Continuous Data – Data that can be measured using scientific tools e.g. height, weight, time or an individual score for each participant.