SECTION B: METHODS OF INVESTIGATION (300 WORDS)

Focus for Section B: Describe the Methods Used to Collect Data Questionnaires – What types of questions? (open, closed) – What topics do questions relate to (questions related to income, number of children, how religious someone is, etc) – How many? Interviews – Description of who will be interviewed – How many?

Justification of Methods The method(s) used must be justified and must enable a sufficient quality and quantity of primary data to be produced to allow the fieldwork question to be investigated. Justify: – Why you ask the questions you do – Why you interview the people you interview – Why you sample using the the method you choose

Sampling Techniques Take out Fieldwork Guide Random Systematic Stratified Must be discussed and decided by entire group. Cannot be an individual decision. If 2 group members use one method and 2 others use another, your data is flawed!

What is sampling? A short-cut method for investigating a whole population Data is gathered from a small part of the whole population and used to inform what the whole picture is like

Why Sample? In reality there is simply not enough time, energy, money, labor/manpower, equipment or access to suitable sites to measure every single item or site within the population. Therefore researchers adopt an appropriate sampling strategy to obtain a representative and statistically valid sample of the whole.

Random Sampling What is it? Least biased of all sampling techniques: there is no subjectivity - each member of the total population has an equal chance of selection. Grid System and Random Point: Demonstrate on board

Random Sampling Strengths – Useful in large populations – Avoids bias Limitations – Can lead to poor representation of general population if general areas are underrepresented – What if 75 of your 100 numbers are in Hegewisch?

Systematic Sampling What is it? Choose samples through a systematic or uniform method. – evenly distributed across a spatial context, e.g. every ½ mile – at regular intervals across a temporal context, e.g. every 10 minutes of walking regularly numbered, every 6 th house on the north side of the street

Systematic Sampling Strengths – More straight-forward than random sampling. – Don’t necessarily have to use a grid … sampling just has to be at uniform intervals. – More easily achieves good coverage of study area than random sampling. Limitations – More biased since not all units have an equal chance of selection.

Stratified Sampling What is it? Used when population made up of sub-sets of known size and that comprise different proportions of total population. Stratified sampling ensures results are proportional and representative of the whole. Example, if you know that 75% of population is Hispanic, they should represent 75% of questionnaires Or dividing into 3 or 4 equal groups based on neighborhood.

Stratified Sampling Strengths – Can use with random or systematic sampling (Stratified Random or Stratified Systematic) – With known proportions of sub-sets, can generate results which are more representative of the whole population. – Can make correlations and comparisons between sub- sets. Limitations – To work properly, the proportions of the sub-sets must be known and accurate. – It can be hard to stratify questionnaire data collection - accurate, up to date population data may not be available and it may be hard to identify people's age or social background effectively.

Section B Sample Close Read Take some time to reread Mathew’s Section B. Highlight/label the following: Description of methods Sampling method description Justification of methods (see what she does with copy of questionnaire)