Define the target population and Select a sampling frame
At the outset of the sampling process, the target population must be carefully defined so that the proper source from which the data are to be collected can be identified. The common technique for defining the target population is to answer questions about crucial characteristics of the population. (Zikmund & Babin, 2007)
The sample that will be used to determine why Castle Lite sales are lower in stores with Castle Lite fridges is chosen following a process of 6 steps (Zikmund & Babin, 2007).
Step 1: Identify target population
The target population is defined according to the research objectives of the study. It was identified that the target population will consist of beer drinkers, because Castle Lite is branded as a premium beer by SAB Limited (SABLimited.co.za, 2010). The target population can be narrowly defined as beer drinkers in South Africa that will consist of people over the age of 18, seeing that South Africa’s legal alcohol drinking age is 18 years, which prevents people under this age from purchasing and drinking alcohol (Department of Industry South Africa, 2004).hier of later?
Step 2: Select a sampling frame
A sampling frame is a list of elements that will be used to draw a sample from the target population (Zikmund & Babin, 2007). It was established that there is no list of beer drinkers currently available; however provincial beer drinker percentages were obtained from Saarf AMPS, 2010. For this reason it is possible that a sampling frame error may occur, because the sample frame may not have certain elements listed or the elements are not accurately represented. This may occur because the researcher may have incomplete information about the target population or the target population is difficult to define accurately.
Step 3: Determine if a probability or non-probability sampling method will be chosen
The sampling method chosen to contact sample members is the non-probability multistage sampling method. This method is chosen because of the possibility that a sampling frame error will occur. All the elements of the target population are not listed thus all the members do not have an equal chance to be selected to take part in the study.( Zikmund & Babin, 2007) This type of sampling method guarantees that the sample will meet a specific objective (Zikmund & Babin, 2007). The disadvantage of this method is that it can result in bias which will lead to that the results of the study are only applicable to the study (Zikmund & Babin, 2007).
Step 4: Plan procedure for selecting sampling units
The target population can be defined as beer drinkers in South Africa that will consist of people over the age of 18, seeing that South Africa’s legal alcohol drinking age is 18 years, which prevents people under this age from purchasing and drinking alcohol (Department of Industry South Africa, 2004).
The working frame was selected in the following phases:
1. Judgment sample: An expert or experienced researcher selects the sample to fulfill a purpose, such as ensuring that all members have a certain characteristic. (Zikmund & Babin, 2007: 432)
For 2010, Statistics South Africa (Stats SA) estimates the mid-year population as 49, 991 300 million. Geographically the researchers used a judgment sample. It was decided to conduct the study in Gauteng, North West and the Western Cape. This decision was made by the following means. The researchers selected the top 5 beer drinker Provinces, which include the following in ascending order; Northern Cape, North West, Gauteng, Free State and the Western Cape. (Saarf AMPS, 2009). It was decided that the study will take place in Gauteng, the North West and the Western Cape in view of the fact that according to Stats SA, 2010 these three Provinces has the largest population proportions.
Beer drinker proportions for each Province population