9. Quantitative data analysis

Question 1

What are descriptive statistics and its two types

Answer 1

• Summary of data set characteristics
• Measures of central tendency: typical / avg
• Measures of dispersion: data spread

Question 2

What are measures of central tendency useful for?

Answer 2

• Comparing performance between groups
• Compare to standard
• Compare to same group over time (eg: before/ after treatment)

Question 3

Mean: meaning, strengths, weaknesses

Answer 3

Statical avg of data set
+ Most representative as uses whole data set
- Most sensitive measures as anomalies can distort value (ordinal, interval data only)

Question 4

Median: meaning, strengths, weaknesses

Answer 4

Central value of data set
+ Not distorted by anomalies
- does not reflect all scores of data set

Question 5

Mode: meaning, strengths, weaknesses

Answer 5

Most common score in data set
+ Not distorted by extreme scores and ONLY ONE that can be done for nominal data
- May have more than one mode therefore not always useful

Question 6

Measures of dispersion

Answer 6

Range: highest score - lowest score
SD: statistical measure of difference of data from mean (higher = greater spread therefore data more inconsistent and vv)