LEVELS & TYPES OF DATA Flashcards
Nominal data
The most basic level of data.
-Data is in separate categories.
-These categories can be allocated numbers, but numbers bare no meaning.
-Closed questions produce nominal data.
-Observations produce nominal data
Strengths of Nominal Data
-easy to generate from closed qs
-large amounts of questions can be collected quickly, increasing reliability.
Weaknesses of Nominal data
-Without linear scale, ps may be unable to express degrees of response.
-can only use the mode as a measure of spread.
Ordinal data
Slightly more precise than nominal.
-Data which can be ranked in ‘order’.
-Needs to be an increase in value of points along you data (numbers of your data DO have a meaning)
-Size of each does not have to be equal
-Units of measurement are not of equal, definable size, cannot tell us gap between 1st and 2nd etc…
-If psychologists record behaviour for each ps individually, data will be ordinal or interval.
-Based on opinion, tend to be subjective rather than objective.
Strengths of Ordinal data
-More info than nominal data.
-Indicates relative values on linear scale instead of just totals.
Weaknesses of Ordinal data
-Gaps between values are not equal, a mean cannot be used to assess central tendency.
Interval data
Most precise
-Has equal intervals, gives more than just order, also shows difference between 1st and 2nd etc…
-Equal intervals could be cm, kg or seconds etc…
-Measurement of time tells us which ps is quickest/slowest, but also by how much.
-If machine can be bought to measure DV such as a thermometer or clock, data is likely to be interval.
Strengths of Interval data
-More info as points are directly comparable as are all of equal value.
-Scientific measures used to record distance between values
-Highly reliable
Weaknesses of Interval data
-No absolute baseline if scientific methods are not used.
-Ps can demonstrate a variable that the scale does not measure.
Ratio
Most precise (Can be classed as same as interval)
-One refinement of interval data is data which has a ‘true zero’ e.g Time.
e.g a temp of 0 degrees does not mean there is no heat (temp is interval data).
However 0 seconds does not indicate time, data with true zero such as time are known as ratio level data, generally treated as interval when it comes to statistical analysis.
Data analysis: nominal data- levels of central tendency=
Mode, frequencies, percentages, pie chart, bar chart.
Data analysis: Ordinal data- levels of central tendency=
Median, mode, range frequencies, percentages, bar chart, pie chart.
Data analysis: Interval/ratio- level of central tendency=
Mean, median, mode
frequencies, percentages
range, variance, standard deviation
bar chart, pie chart, histogram.
Primary data
Researcher collects data witnessing an event or carrying out experiment, questionnaire etc.
Can be quantitative or qualitative.
Collected first hand by researcher.
(experiments, observations, interviews, questionnaires)
Strengths of Primary data
-gathered first hand following careful operationalisation
-more trustworthy therefore more valid
-high internal validity as collected for purpose of study