purposive sample was also employed for the study. The reasons for the choice of these two sampling techniques are explained below.
Simple random sample
The sampling method adopted for this study was the simple random sampling technique. This sampling method provides an equal chance for each member of the population to be selected within the sample. A sampling frame is first identified or constructed by the researcher to
determine the ideal sample size before the data is collected. A single number is then assigned to each element in the list. Numbers are then picked randomly from the list of registered names in the sampling frames which constitute the elements or actual sample from which the study will be conducted. This procedure can be conducted either manually using a statistical table of numbers or by a computer program. Using a computer program is considered more convenient and less time consuming and is much preferred when dealing with a large sample (Sarantakos, 1998: 143;
Babbie, 2004: 202). The sampling process for this study was done manually using the statistical table of numbers developed by Krejcie and Morgan (1970: 163). For the purpose of this study also, the simple random sampling method was considered more effective for obtaining
representative results from the sample. This choice was made because the simple random selection process underlies the validity and credibility of sample data which in turn affects the level to which sample results can be generalised to the study population. Similarly, a distinct advantage of probability sampling method is that it provides the researcher with the means to remove any probable errors that may be associated with the particular sample (Bickman & Rog, 2009: 84).
Purposive sample
A purposive sampling technique is designed to pick a small number of cases that will provide the needed information about a particular phenomenon (Tashakkori & Teddlie, 2009: 292). It
involves selecting a sample on the basis of the researcher’s knowledge of the study population in terms of its various elements and how it fits into the nature and aims of the research (Babbie &
Mouton, 2001: 166; Fogelman & Comber, 2007: 135). In purposive sampling, respondents may be selected for their representativeness of a larger population but are likely to be chosen for the kind of information they may provide. The choice of a purposive sample may be done if it is
considered that a random sample may not yield the desired result (Mabry, 2008: 223). Purposive sampling can occur before or during data collection. The reason for the choice of this sampling method was informed by the decision to use the reflective journals produced by the aspirant barristers as a method of data collection. It was considered that since it may not be possible for the researcher to analyse all the journals produced by the aspirant barristers, a purposive sample could be used to select a sample that will be relevant to the findings of the study.
In mixed methods research, it is possible to employ both purposive and probability sampling techniques. The researcher’s ability to creatively combine these techniques in answering the research questions allows the researcher to generate complementary databases that include information that has both depth and breadth regarding the case under study (Tashakkori &
Teddlie, 2009: 292). Both sampling techniques were deployed in the conduct of the study.
4.5.3. Sampling frame
A sampling frame is the actual sampling unit from which a sample is selected from the target population; it is usually drawn by obtaining a list of the study population (Babbie & Mouton, 2001: 174). Sampling frames have inherent flaws which may be as a result of missing or duplicated elements within the list of the total population. According to Henry (1990: 88) the challenge of an efficient sampling method is to find a means to reduce total errors as this can have a bearing on the overall research design in that the aim should be to reduce bias and discrepancy in the sample and the study population.
The sampling frame for this study comprised a comprehensive list of accredited law firms in Nigeria which are organised in the database of the Nigerian Law School. The list is
representative of the six geo-political zones of Nigeria and has a total of three thousand and three (3003) law firms compiled by the Nigerian Law School as placement areas for the aspirant barristers within the course year (Grimes, 2009: The reforms; Oditah, 2006: Expanding the scope of law practice in Nigeria). From this list a sample was drawn of 341 law firms using guidelines from Krejcie and Morgan (1970: 163). The reason for choosing to undertake the sampling procedure from this list was based on the consideration that undertaking the study through a coordinated body like the Nigerian Law School to which all the deans of the thirty five
accredited university law faculties, as well as the Nigerian Bar Association, have considerable input would be more practical in terms of producing outcomes that could influence future policy decisions about the conduct and practice of law in Nigeria (Elias, 1962: 118-119).
The sampled list of the law firms were then organised alphabetically according to the 36 states of Nigeria, including names of law firms, addresses and local government councils/municipalities in the selected states. Provision was also made in the list for alternative law firms to be contacted (these were also selected from the database of the NLS) in case the researcher was unable to locate the sampled law firms. However, of the 36 states of the federation, due to the sampling process used, four states were not selected. This left a total of 32 states for the study, including the Federal Capital Territory (FCT), Abuja.
A list of 4500 aspirant barristers registered for the course year at the Nigerian Law School was used as the sampling frame. From this list, a sample of 354 aspirant barristers was drawn, also using guidelines from Krejcie and Morgan (1970: 163). A minimum of two to five aspirant barristers are usually assigned to each firm for the attachment programme exercise depending on the size of the law firm.