Data Analysis: Graphs

Question 1

Scattergram:

Answer 1

A type of graph that represents the strength and direction of a relationship between co-variables in a correlational analysis.

Question 2

Bar Chart:

Answer 2

A type of graph in which the frequency of each variable is represented by the height of the bars.

Question 3

Summarising data in a table:

Answer 3

1. When tables appear in the results section of a report they are not merely raw scores, but have been converted to descriptive statistics.
2. Standard practice to include a summary paragraph beneath the table explaining the results.

Question 4

Bar Charts:

Answer 4

1. Suitable graphical display so the difference in mean values can easily be seen.
2. Bar charts are used when data is divided into categories, discrete data.
3. Categories on the x axis and frequency or amount of each category is plotted on the vertical y axis.
4. Bars are separated to denote we are dealing with separate conditions.

Question 5

Scattergrams:

Answer 5

1. Scattergrams do not depict differences but associations between variables.
2. Either of the co-varibales occupies the x-axis and other on the y axis.

Question 6

Normal Distribution:

Answer 6

1. Should form a bell curve, which is symmetrical.
2. Most people in the middle, very few people at the extreme ends.
3. Mean,median and mode all occupy the same mid-point of the curve.
4. The tails of the curve never touch the horizontal x axis, as more extreme values are always theoretically possible.

Question 7

Skewed Distribution:

Answer 7

1. Distribution appears to lean to one side. Positive skew is where most of the distribution is concentrated towards the left of the graph, long tail on the right.
2. Negative skew, bulk of scores are concentrated on the right, long tail of anomalous results on the right. Mean pulled to the left, mode peak, median middle.