Unit 5: Data Analysis and Reporting

Question 1

Descriptive statistics

Answer 1

Techniques for summarizing and displaying data.

Question 2

Frequency table

Answer 2

Column 1 lists each value a variable could have (ex: score on a test).

Column 2 lists the frequency of each value/score

Used to describe characteristics of a single variable in a data set:

• range
• most and least common values
• outliers

Question 3

Histogram

Answer 3

A graphical representation of a distribution, such as a frequency table.

x-axis = variable
y-axis = frequency

Question 4

Distribution shape

Answer 4

1. Unimodal - has one distinct peak, and tapers on either side
2. Bimodal - has two distinct peaks

Question 5

Standard error

Answer 5

The standard deviation of the group, divided by the square root of the sample size.

A difference between two group means that is greater than 2 standard errors is considered statistically significant.

Question 6

Error bars

Answer 6

Used to represent with-in group variability.

Are added to bar and line graphs to display a standard error, to visually represent whether variability is statistically significant.

Question 7

Line graphs

Answer 7

Used to represent correlations between quantitative variables, when the independent variable has (or is organized into) a relatively small number of distinct levels.

Typically used when the variable on the x-axis is quantitative (rather than categorical)

Question 8

Bar graphs

Answer 8

Used to present and compare the mean scores for two or more groups/conditions.

Typically used when the variable on the x-axis is categorical (rather than quantitative)

Question 9

Scatterplots

Answer 9

Used to present relationships between quantitative variables when the variable on the x-axis has a large number of levels.

Each point represents an individual score (rather than the mean for a group of individuals)

Can include a regression line (a straight line of best fit)

Question 10

APA Style - key features

Answer 10

1. Few direct quotations of other researchers.
2. Criticisms are directed at other researchers’ work, but not the researchers personally
3. Many references and citations
4. Reports are organized with specific sections in a fixed order
5. Researchers tend to “hedge” their conclusions (“results suggest that…”)

Question 11

APA Style - 3 basic levels

Answer 11

1. Organization - title page, abstract, introduction, method, results, discussion and references
2. High-level style - guidelines for the clear expression of ideas (formal, straightforward, unbiased towards particular groups)
3. Low-level style - guidelines for spelling, grammar, references, citations, numbers and statistics, figures and tables, etc