Research Methods L13-16

Question 1

What is quantitative data?

Answer 1

Numerical data that can be measured objectively.
Includes:
- DV in an experiment.
- closed questions (questionnaire)
- structured interviews. Etc.

Question 2

What is qualitative data?

Answer 2

Data involving words which is only quantifiable if put into categories and the frequency is counted.
Includes:
-open questions.
- transcript from unstructured interview.
- researchers describing what they see in an observation.

Question 3

Advantages and disadvantages of quantitative and qualitative data?

Answer 3

Quantitative:
\+ easy to analyse.
- provides limited information.
Qualitative:
\+provides detailed info.
- relies on interpretation by the researcher which could be subjective/biased/inaccurate.
- difficult to categorise.

Question 4

What is primary data? +/-?

Answer 4

Data that is collected directly by the researcher fir the purpose of the investigation.
+ up to date.
+ reliable.
- time consuming.

Question 5

What is secondary data? +/-?

Answer 5

Data that was collected for a purpose other than the current use.
+saves time and money.
- lack of reliability.
- data may have changed over time

Question 6

What is a meta-analysis? +/-?

Answer 6

The process of combining results from a number of studies on a particular topic (secondary data) go provide an overall view.
+ results can be generalised across large populations.
+ increases validity
- prone to publication bias. Researcher may leave negative results out.

Question 7

What are the 4 ways of representing quantitative data?

Answer 7

1. Tables (with explanation paragraph below).
2. Scattergraph.
3. Bar chart.
4. Distributions.

Question 8

Scatter graph?

Answer 8

A graphical display that shows the correlation or relationship between two co-variables.

• indicates the strength and direction of the correlation between the co-variables.
• dots are plotted to represent each pair of scores.

Question 9

Bar chart?

Answer 9

Used to show frequency for discrete (separate) variables.

• height of each bar represents frequency.
• space left between each bar to indicate lack of continuity.

Question 10

Distributions?

Answer 10

• Normal distribution = symmetrical curve. The mean, mode and median occupy the same midpoint of curve.
• positive skew= data mostly concentrated to left of the graph. Mode remains at highest point of peak, then median and mean dragged across to right.
• negative skew= opposite of +.

Question 11

What are the measures of central tendency?

Answer 11

Mean, median, mode

Question 12

What are the measures of dispersion?

Answer 12

Range, standard deviation.

Question 13

Mean? +/-?

Answer 13

Calculated by adding all the scores and dividing by the number of scores.
+ representative of all data.
+ most sensitive measure of central tendency.
- can be distorted by a single extreme value which will give inaccurate results.

Question 14

Median?+/-?

Answer 14

Calculated by arranging scores in order and choosing the numerical midpoint.
+ unaffected by extreme values.
- less sensitive than mean.
- not representative of all findings.

Question 15

Mode? +/-?

Answer 15

Most frequent value in a data set.
+ unaffected by extreme values.
- tells nothing about other values in the data set.

Question 16

Range? +/-?

Answer 16

Calculated by taking lowest score from the highest.
+ quick and easy to calculate.
- easily distorted by extreme values.

Question 17

Standard deviation? +/-?

Answer 17

Is the average amount that each score differs from the mean.
+ takes all values into account.
- more difficult to calculate than range.

Question 18

Percentages?

Answer 18

(Number in pps in condition / total pps) x 100

Question 19

What is the sign test and when is it used?

Answer 19

The sign test is a statistical test of difference that allows a researcher to determine the significance of their investigation.
It is used in studies that have repeated measures design (one group of pps) and when data is numerical.

Question 20

How is a sign test carried out?

Answer 20

1. State the hypothesis:
   - directional hypothesis = one tailed test.
   - non directional hypothesis = two tailed test.
2. Record data and work out sign: subtract before value from after value. Write a sign (+ or -)
3. Find calculated (S) value:
   - calculate separately how many + and - signs. Smaller value = S.
4. Find critical value:
   - N = total number of scores. Use table of critical values to find the critical value.