Sampling Procedure

Before data could be collected in research, effective sampling procedures needed to be adopted. Sampling procedure involves determining the location, population, sample size, and the recruitment procedures for participants and respondents (Saunders, et al., 2012; Creswell, 2015). Denscombe (2010) also stated that before adopting a sample for a study, it is important to determine the following:

 Sample population refers to the items in the category of things that are being studied rather than the total people in a country

 Sample frame: contains the information about the sample population which can take the form of list of names addresses or contacts of those represented in the sample population from which the sample size will be collected

140  Sample size refers to the items within the category of the sample population that have

been selected to be involved in the study.

Saunders et al. (2012) pointed out that sampling is needed because it is impractical to survey or interview an entire population. Therefore, to maximize efficiency and validity sampling procedures are applicable both quantitative and qualitative investigations.

Probability and non-probability approaches are the two main sampling approaches. Probability sampling is employed to draw a representative sample from the population so that the results of a study can be generalised from that sample to the population. However, this may not fulfil the informational needs of the study and is clearly described suitable for quantitative investigations. In the probability sampling procedure, the target samples are selected through a process that gives equal chances of selection to all the individuals in the sample population. The techniques include the random, systematic, cluster and multi-stage and the stratified sampling techniques (Denscombe, 2010). On the otherhand, non- probability sampling aim is to provide illumination and understanding of complex issues which implies that the sample selected. Examples are quota, purposive, snowball, purposeful, convenience and theoretical sampling techniques (Denscombe, 2010: Saunders et al., 2009). This approach is not for the purposes of statistical representation or operate on the principle of random selection to obtain target samples but rather by pure chance. It is applied where smaller sample population is required and mostly associated with qualitative studies.

However, research may combine the use of both sampling approaches. According to Onwuegbuzie and Collins (2007) both probability and non-probability sampling approaches are required to drawn inference for purposes of completeness or confirmation in mixed method research designs. Though Yin (2009) and Thomas (2011) maintains that probability-sampling logic is not much emphasised in case studies because it covers both the phenomenon of interest and its context, yielding a large number of relevant variables that will require too many cases to allow for any statistical consideration. Therefore, in this study, for the purposes of collecting both qualitative and quantitative data from the case participants a purposive sampling technique is adopted.

141

3.8.4.1 Within case sampling of participants

The research adopted a non-probability sampling techniques following a strategic process to ensure that the participants selected for the semi-structured interviews were able to provide in- depth information on the CMS employed on the LcH projects in the Nigeria southeast zone. First, there was need to select LcH based on certain criteria:

 Variance in project sponsors,

 location of the project within the Nigerian southeast zone,  accessibility to the PMT members,

 projects all experienced poor cost performances,

Four key LcH projects (two each from federal and state level within the zone) that met these criteria were selected. As stated by Amaratunga and Baldry (2001), this sampling technique projects theoretical sampling, which they described as most suitable for case studies as it aids theory development and generalisation to theoretical propositions. These project are anonymised with PA, PB, PC and PD and an overview the projects’ information is as detailed in Table 3.7.

Table 3. 7: Selected projects information

Source: Researchers Field Survey (2015)

Characteristics PA PB PC PD

Project type State-Led LcH project Federal led LcH project

No of Housing Unit 67 75 units 120 units 50 units

Average Square Area

85m2 92 m2 82m2 85 m2

Procurement type Design-bid- build Design-bid- build Design build Design build Project Cost per 2

bed unit

4.575 million 4.16million 5.5 million 5.5million

Final Total Cost 6.398 million 5. 1 million 7.99million 8.62million Project cost Performance 40 percent cost overrun 23 percent cost overrun 45 percent cost overrun 57 percent cost overrun Commission 2011 2014 2014 2013

Status Completed in 2014 Sectional completion

Sectional completion

Sectional completion

142 The interviewees were selected based on their participation and organisations involvement in four selected LcH projects. The participants purposively selected were PMT members representing the consultants, housing agency, and contractor site teams. The target participants were all construction professionals: quantity surveyors, architects, engineers, and builders. Their roles cut across project managers, project supervisors, project consultants, site managers, and supervisors. It is presumed that these participants based on their educational and professional roles well as members of the PMT on the selected LcH projects are well informed and will be able to produce the valuable data needed for the study.

In stage two of the research process, 40 participants were approached, 28 agreed to participate, but only 23 were available for the interview. A breakdown of the sampling frame of participants is presented in Table 3.8. Each participant selected were approached with due ethical process and approval. The interviewees and their organisation were anonymised using representative descriptors HAST, CST and CNT.

Table 3. 8: Sampling frame for semi-structured interview Participants

HAST connote staff representing housing agency supervision team, CST staff representing the project consultants team and CNT staff representing project contractor team.

The semi-structured interviews were conducted face to face with the participants. The reason for choosing the face to face interview is that it gives the researcher the opportunity to directly

Project organisation

Project management

team

Interview participants Total

Participants State-led LcH projects Federal- led LcH projects

Housing Agency In-house

supervisory team(HAST) 4 3 7 Consultancy organisation Project consultant team (CST) 4 4 8 Contracting Organisation Project contractor management team (CNT) 4 4 8 Total 12 11 23

143 meet with the participants and affirm the relevance of the person to be interviewed in relation to the topic studied. All the interview participants were briefed on the purpose, objectives of the research.

3.8.4.2 Within case Sampling of respondents

For the purposes of collecting quantitative data via questionnaires, the researcher also employed purposive sampling to select respondents. First, the researcher tried to identify the project organisations who had and are involved in LcH project delivery in the zone. Owing to the lack of a published list of these organisations, the researcher contacted the housing agencies within the various states in the zone and searched for a list of ongoing and recently completed LcH projects. Furthermore, the researcher also employed experiential knowledge and publicly available information to ensure that ongoing and recently past completed LcH projects within the past 10 years situated in the southeast zone of Nigeria were captured and crosschecked with the list compiled. From a complied list of the projects, eighty-three (83) organisations were identified. Given the manageable number of the project organisations, the researcher sent three questionnaires each to all the identified organisations totally 249 distributed questionnaires. Table 3.9 shows the distribution of the questionnaires amongst the identified organisations. The target respondents were project staff who were quantity surveyors, architects, engineers and builders. These experts were presumed knowledgeable on the topic area and could produce the most valuable data needed for the study.

Table 3. 9: Questionnaires Administration

Source: Field study, (2015) Number of project organisations No of questionnaires distributed No of questionnaires Returned Response rate 10 Nr Housing Agencies 30 26 86.67% 31 Nr Consultancy organisations 93 57 61.29% (42 Nr) Contracting organisations 126 61 48.41% Total 249 144 57.83%

144 A response rate of 57.83 percent was obtained. This rate was considered acceptable following results of similar investigations in the context (Ihua, et al., 2014) and the low response rates commonly associated with questionnaire surveys. According to Fellows and Liu (2015), postal questionnaires can expect a 25 to 35 percent response rate, while Sekaran (2006) is of the view that a 30 percent response rate is acceptable. However, in this case, the response rate was far above 30 percent.