Data Collection (AQA GCSE Geography)

• Data which records quantities is quantitative data
• Examples of quantitative data are:
  • Numerical data collected in questionnaires
  • Traffic counts
  • Environmental quality surveys
  • River data: velocity, discharge
  • Weather data
• Data which records descriptive information is qualitative data
• Examples of qualitative data:
  • Field sketches and photographs
  • Non-numeric questionnaire data
  • Interview answers

Questionnaires and interviews

• When collecting data via questionnaires or interviews a number of questioning types can be used:
  • Closed questions where answers are limited to single words, numbers or a list of options
  • Statements which use a scale to gauge people's views. For example, strongly agree/agree 
  • Open questions where the respondent can give any answer
• Questionnaires can be used to gather a large sample of data
• Interviews are more in-depth and tend to be used to gather a smaller data sample

Environmental quality surveys

• These are used to collect data about the environmental quality of different sites
• They use the judgement of the person conducting the survey to assess environmental quality against a range of indicators
  • Using a sliding scale (1 -5) or bipolar scale (-3 to 3)
  • Usually, the lower the score the more negative the assessment of the environmental quality
• They are subjective because they are based on the opinion of the person completing them
• This can be reduced by:
  • Completing in small groups to reach a consensus regarding the score
  • Using the mode of EQS completed by a number of students
• They produce quantitative data

Purpose of Sampling

• It gives an overview of the whole feature/population to be sampled
• There is not enough time/equipment/access to measure the whole area being examined
• Sampling provides a representative and statistically valid sample of the whole

Types of Sampling

• There are three types of sampling to consider
  • Random
  • Systematic
  • Stratified
• Random sampling
  • A grid is drawn/placed over the area to be studied
  • The squares which include part of the study area are numbered
  • The numbers are entered into a random number generator 
  • The samples should be collected as near as possible to the points given
• Systematic sampling
  • The samples are selected at regular intervals for example every 500 meters or every tenth person
• Stratified sampling
  • Used when the study area includes significantly different parts known as subsets 
  • Is based on the idea that the sample represents the whole population 
  • If a questionnaire is being used to collect data and the population of the study area has 10% of people over 65, then the sample should include 10% of people over 65

• All sampling methods have advantages and disadvantages