Descriptive statistics

Question 1

What are the**Types of data **?

Answer 1

1. Primary data
2. Secondary data
3. Qualitative data
4. Quantititative data
5. Meta-analysis

Question 2

Primary data

Answer 2

*Data obtained from the participants directly *
- Time consuming and expensive to obtain & analyse
+ Collected first hand- has not been altered by others
+ Gathered for the purpose of study

Question 3

**Secondary data **

Answer 3

Data that has already been collected from other researchers
+ Quick & cheap
- Information may be outdated or incomplete

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Question 4

**Qualitative data **

Answer 4

*Descriptive data based on thoughts, opinions & feelings *derived from open-ended questions
+ Gives richer detail
- Difficult to analyse

Question 5

Quantitative data

Answer 5

Numerical data, derived from *closed-ended questions *
+ Easy to analyse
+ Much more reliable
- Oversimplifies behaviour

Question 6

Meta-analysis

Answer 6

**Reviewing & comparing the findings of previously conducted research studies **
+ Less time consuming because study has already been done
+ Inexpensive
- Reling on other people, so mistakes & bias affect your results

Question 7

**Levels of data **

Answer 7

1. Nominal Data
2. Ordinal Data
3. Interval Data

Question 8

Nominal Data

Answer 8

Categorical variables, it classifies things
e.g gender: female / male
colour: blue, green, brown, black

Question 9

Ordinal Data

Answer 9

Categories are rank ordered
They indicate a greater than relationship but dont show how much greater
e.g Olympic marathon results- first to last
Exam results - A* - U

Question 10

Interval Data

Answer 10

Measurement on a scale
They have *equal units of measurements *
e.g temperature, time, weight, height
Exam results- using % and scores instead of grades

Question 11

Measures of central tendancy

Answer 11

Tendancy: Inform researchers of the average for data collected

Question 12

Mean

Answer 12

The average score
* all scores are added together & divided by the numer of scores
+ *Considers the average of all *the numbers in data
- Can be distorted by extreme values, may not be accurate

Question 13

Median

Answer 13

The middle value of data
* All *scores are placed in order and middle value is identified *
+ Unaffected by extreme values
- Only takes into account one/two values and does not represent the whole data set

Question 14

Mode

Answer 14

Most common score in data set
* All scores are placed in order and most common is identified
+ Unaffected by exterme results
- Can be affected by extreme change in score and doesnt represent whole data set

Question 15

Measures of dispersion

Answer 15

Dispersion: Inform researchers of how spread out the data is

Question 16

Range

Answer 16

Difference between the smallest and largest number
* All scores are placed in order and smallest is taken away from largest
+ Easy to obtain
- Does not take into account values

Question 17

Standard Deviation

Answer 17

• Describes how much *dispersion there is around the mean *in the data set
  + Takes into account every score
  - Easily distorted by extreme values
• The** lower the standard deviation, the better** because it shows more consistency between the results

Question 18

Visual Representation of Data

Question 19

Scattergraph

Answer 19

• Used for the *correlation analysis/ to show the relationship between co-variables *
• One of the co-variables is plotted on the x-axis and the other is plotted on the* y-axis*

Question 20

Bar graph

Answer 20

• Used to display categorical data
• Bars are seperated to show we are dealing with seperate conditions

Question 21

Histogram

Answer 21

• Bars touch eachother to show that data is continous

Question 22

Line Graph

Answer 22

• Also represent* continuous data *and use points connected by a line to show how something changes in value

Question 23

Distribution graphs

Answer 23

• Show measures of central tendancy
  1. Normal distribution graph
  2. Positive graph
  3. Negative graph

Question 24

Normal distribution graph

Answer 24

• Bell-shaped curve
• Mean, mode, median occupy the* same midpoint* of the curve
• There is a balanced symmetrical pattern

Question 25

Positive Skew Graph

Answer 25

• Most of the* distribution is concentrated towards the left of the graph *
• Mean is the lowest score, median is the middle and mode is the highest score

Question 26

Negative Skew Graph

Answer 26

• Most of the distribution is concentrated to the right of the graph
• Mean is the lowest score, median is the middle and mode is the highest

Question 27

Computation

Answer 27

• Fractions
• Decimals
• Percentages
• Ratio
• Range
• Significant Figures