Using primary and secondary data

Primary data

Primary sources of information are gathered by the designer and used to help improve their designs:

  • Market research - Looking at products that already exist and talking to clients to collect a wide range of information on what is successful and what needs developing to ensure a product is viable. Interviews and questionnaires can be used to gather information on shape, colour, materials and function of existing products and the answers analysed to improve the product.
  • Focus groups - Another valuable perspective can be found by talking to the product’s target market. Small groups can be interviewed, giving feedback before, during and after production, which can be used to improve the outcome.
  • Product analysis - Looking at products that already exist can help improve further designs by pinpointing issues to improve designs and prototypes.
  • Anthropometrics - Collecting maximum and minimum measurements about the target market’s sizes can help improve designs by making the product easier or more comfortable to use. Anthropometric data can be used to work out the dimensions and load stresses of a product.
  • Ergonomics - Testing and analysing how a person interacts with the product can improve its functionality and how it fits into its surroundings.

Secondary data

Secondary sources of information use data already found by other people or organisations that are relevant:

  • Existing data - Average anthropometric and ergonomic measurements are available online, as well as government statistics and a huge range of questionnaires and public opinion.
  • Media - Books, newspaper articles, reviews and the internet all provide access to the opinions of others.

Presenting data

Data from questionnaires can be presented visually using graphs, pie charts and tables, making it easier to analyse and summarise. Anthropometric and ergonomic details collected can be averaged out to find the sizes that fit most users. The average measurement percentile is typically the biggest group of users sharing a measurement.

A generic pie chart, bar chart and line graph to show visual ways of representing data.Pie chart, bar chart and line graph

Example

In order to design a new shoe rack for a classroom, it would be useful to know the most common shoe size in the class. To record the data, a combined tally chart and frequency table will need to be produced, as shown below:

A tally chart and frequency table for the most common shoe size in a class - size four has three tallies, five has eight, six has five, seven has three and eight has one.

Using a tally chart speeds up the process of recording data - the tally is added together to give the frequency. To produce a bar chart of this data, the UK shoe size could go along the x-axis and the frequency along the y-axis:

A bar chart for the most common shoe size in a class - UK shoe size is along the x-axis and frequency goes up the y-axis.
Question

Below is bar chart of the handspan of students in a class:

A bar chart for the handspan of students in a class - handspan in millimetres is along the x-axis and frequency goes up the y-axis.

Use the bar chart to complete the missing data in frequency table below:

Handspan (mm)Frequency
100 ≤ × < 110
110 ≤ × < 120
120 ≤ × < 130
130 ≤ × < 140
140 ≤ × < 150
Handspan (mm)Frequency
100 ≤ × < 1103
110 ≤ × < 1202
120 ≤ × < 1305
130 ≤ × < 1404
140 ≤ × < 1501