Types Of Data And Descriptive Stats

Question 1

Difference between primary and secondary data

Answer 1

Primary is data gathered directly from the ps by the researcher. Secondary is data already gathered by someone other than the researcher

Question 2

Strengths and weaknesses of quantitative data

Answer 2

S: easy to analyse statistically and, quick to collect and compare W: lack depth and detail about behaviour, lacks insight into explanations

Question 3

Strengths and weaknesses of qualitative data

Answer 3

S: richer and more detailed data, provides insight into explanations for behaviours W: difficult to analyse and more time consuming

Question 4

What are the levels of data in ascending order

Answer 4

Nominal, ordinal, interval or ratio

Question 5

What is nominal data and an example

Answer 5

A headcount of the number of ps who do one thing as opposed to another e.g no. Males who ate fruit at lunch and no. of those who didn’t (forced choice or tallying)

Question 6

What is ordinal data and an example

Answer 6

Data that can be placed in rank order from lowest to highest. Analysis done of rank but no account taken of how much further first is from second e.g. in competition to think of number of uses for an item analysis is who came up with most uses second most uses.. (data from rating scales or non standardised tests like memory test score)

Question 7

What is interval or ratio data and an example

Answer 7

Takes into account rank and actual individual results (how much higher one is) made possible by using calibrated measures with equally sized intervals (anything like g.kg.m.temp.time) e.g ps given word search and were time in how long it took them to complete . Both are measurements on a scale but ratio has true 0 point like distance or time can’t go minus but interval can go into negative values like temp

Question 8

Strengths and weaknesses of the mean

Answer 8

S: more sensitive to use if no outliers easy, takes into account all data so more accurate than median to calculate, presents central point of a distribution curve w: may not be representative, affected by extreme scores

Question 9

Strengths and weaknesses of the median

Answer 9

S: not affected by extreme scores, W: can be distorted by small samples

Question 10

Strengths and weaknesses of the mode

Answer 10

S: not influenced by extreme scores, can deal with non numerical data W: not useful if many equal modes

Question 11

What are the measures of dispersion + strengths and W of range

Answer 11

The range (biggest take smallest). Can be displayed on a bar chart using range barsS: quickly see how dispersed results are W: no indication is scores are evenly distributed and can be skewed by a very high or low score. variance and standard deviation

Question 12

What is the variance, S and W, + how to calc

Answer 12

Shows how spread apart the data is within each condition from the mean, the smaller variance the less spread the scores are from the average score. S: takes in account of all the values in a data set so not affected by outliers. W: figure not in same units as original as squared 1. Calc mean score per condition 2. For each p, subtract mean from their score which gives difference (d) 3. Square each score (d squared) 4. Add all of d squares together (separate for each condition) 5. Divide the sum by n-1 (no. Ps in that condition-1)

Question 13

How to calculate the standard deviation and what does it mean , S and w

Answer 13

Square root of the variance. shows how far scores are spread from the mean S: all values taken into account and in the same units/ answer much more typical of the actual difference and data collected, variance is a bigger/untypical figure as squared. W: time consuming and more difficult to calculate than range

Question 14

When is a histogram used

Answer 14

For continuous data e.g age. There should be no space between the bars categorical data e.g. likes vegetables and doesn’t is for a bar chart. Show frequency density on the y axis and age range on the x axis (count accurate scale). Area for each bar (height x width) is the frequency and to work out frequency density (frequency divided by width) width is the age range,length freq dens?

Question 15

Find practice questions with histograms and bar charts also any other things from standard form, scatter graphs or line graphs and practice decimal places/sig figs

Answer 15

Do it!

Question 16

What to remember when doing any maths question

Answer 16

WRITE OUT EVERY SINGLE STAGE OF WORKINGS!

Question 17

S and Weakness of ordinal data

Answer 17

S: more info than nominal data W: Don’t know the difference between ranks as not an objective measurements so don’t know how much someone likes something more than someone else , cant measure central tendency?

Question 18

S and W of interval data

Answer 18

S: tells you how much better one rank is as has standardised measurements, reliable as uses standard scale, can do mean, mean and mode? Put in graph/stat test W: ps can demonstrate a variable the scale doesn’t measure, ?, not comparable as no base 0

Question 19

S and W of ratio data

Answer 19

S: values direction comparable as have true 0 W: lack of detail/reasoning

Question 20

Can you treat ratio data as ordinal

Answer 20

Yes

Question 21

S and W of nominal data

Answer 21

S: easy to collect, analyse. Can present in graphical format, carry out stat test W: no reasons for behaviour, easy to miss behaviour, can be misinterpreted, can’t calc mean, median as don’t have individual scores

Question 22

S and W of primary and secondary data

Answer 22

Primary S:original data specific to needs W:time consuming and cost secondary:S:quickly and less cost as already there, W:may not be useful, hard to obtain?