Page 4: Quantitative and qualitative research
Quantitative research presents information numerically, for example, by use of percentages. All respondents in interviews or questionnaires answer the same questions to ensure consistency.
For example, the following question was used before and after the advertising campaign:
'How often, if at all, do you use information on salt, fat, sugar or saturated fat on the FRONT of the pack when it is available when choosing which food product to buy?
01: Never/Not seen 02: Rarely 03: Occasionally 04: Usually 05: Always 06: Do not purchase food'
The results of this question for the period before and after the advertising campaign were shown as a chart to make it easy to understand.
Qualitative research finds out opinions through open-ended questions. The FSA used primary qualitative research when designing the traffic light scheme. It talked to small groups of medical professionals, consumers and government advisers.
It also used secondary research taken from scientific studies by bodies like Diabetes UK. This helped the FSA to gather all relevant information to ensure that the scheme would fulfil requirements.
By using both quantitative and qualitative research, the FSA was able to maximise the range of data available for effective analysis. For example, it commissioned a survey of 2,000 adults using Computer Assisted Personal Interviewing (CAPI). This plays the TV adverts and shows posters and press adverts to respondents.
Each interviewer had a random quota of people. The interview group had a mix of gender, age and working status to ensure a representative sample. A sample is a small part of something intended as representative of the whole group. For example, it would be impossible to survey the whole country. By using a carefully selected sample, the FSA analyses and makes judgements about what the overall trends are. By analysing sample data, the FSA can draw conclusions about what the results would be for the larger group.