VALIDITY AND RELIABILITY

For a research to be scientifically acceptable, it must be valid and reliable (De Vos, Strydom, Fouche & Delport 2005: 162-163). Validity and reliability can be accomplished by implementing an acceptable research design for the study. According to De Vos et al. (2005: 162), validity mainly pertains to the accuracy of the research instruments in measuring what they are supposed to measure. Reliability relates to the ability of the research design to be replicated and bring the same results (De Vos et al. 2005: 162-163). If a research design is repeated and brings different results, then it can be deemed unreliable. A study should satisfy both validity and reliability for it to be accepted. Multiple units of analysis were drawn from all areas of the Harare industrial sector to ensure adequate coverage. The researcher ensured that anonymity and confidentiality were maintained when collecting data. The same questions were asked throughout the interviews by utilising the interview schedule. The researcher ensured that the questions in the interviews and questionnaires were suitably understood by the respondents. The instruments contained questions of fact on existing security systems and opinion on integration of security systems. In instances where the responses were ambiguous, the researcher sought for clarification from respondents during interviews.

Corroboration was attained through the use of combined methods of data collection in the form of observations, interviews and questionnaires. The information obtained from interviews was compared with questionnaire responses as well as field notes taken by the researcher. Individuals used in the focus group discussion for pre-testing the instrument were excluded in the main study.

34 2.8.1 Validity

For a study to be valid, all outside interventions or influences (extraneous variables) must be excluded from the research design (Marczy, et al. 2005: 174). These unrelated influences may be erroneously included in sampling, interview and questionnaire design. In the context of interviews and questionnaires, these can be in the form of leading questions, double barrelled and ambiguous questions. In order to ensure internal validity, the researcher pilot tested the interview and questionnaires through a focus group discussion to remove any potential errors in the draft questions. During the sampling process, adequate safeguards against selection bias were made although this could not be totally avoided owing to the non-random sampling techniques used. The researcher selected industrial units of analysis so that they were evenly spread out in each of the five industrial areas. Security service companies selected were from different organisations of each industrial area included in the study. During the course of the study, the researcher ensured that no provide special treatment to any participants.

External validity refers to the extent to which the research results can be generalised to other situations similar to the area of study (Marczyk, et al. 2005: 190). In order to ensure external validity, the researcher should avoid any selection biases or undue loss of a large number of participants. If the final respondents are substantially reduced in number, the research may be externally invalid. In carrying out literature review, the researcher consulted recent sources of information to prevent the effects of maturation. Out-dated information may not be appropriate for contemporary security management issues. The themes in the questions were derived from the McKinsey 7-S framework and the Rogers Security Risk Management Model which are reputable models and were considered relevant to the study. The themes in the research instruments were arranged in a consistent fashion. In questions were the Likert scale was used, the responses were grouped according to the themes. The potential loss of units of analysis through refusal or drop outs was safeguarded by having extra units in the permission letters. It was foreseen that some units of analysis could refuse to participate in the study thus necessitating obtaining sufficient permission letters.

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The collection of information was done by the researcher without any outside assistance. Use of untrained field workers could have impacted negatively on the validity of the study. Respondents who participated in the interview did not participate in the survey questionnaire and vice versa. The researcher engaged both the direct and indirect method of collecting information. Cross validation through literature review and observations was utilised. Participants used in the pre- tests were not part of the main study. Literature review was to some extent used for triangulation with information collected from other sources. Statistical tests were carried out using SPSS to determine relationships on collected data. Cappers (2008: 94) alludes that the mixed method approach of the research design enables triangulation of information from different sources through a combination of qualitative and quantitative approaches; hence the researcher found the approach to be suitable for the study.

2.8.2 Reliability

Reliability refers to the acceptance of the research for application in other areas outside the case study but with similar characteristics. The findings and recommendations on integrated security systems obtained from the study can be implemented in other set-ups where integrated security systems are used. The researcher ensured reliability by removing bias from sample selection and design of the research instruments. However, it is difficult to completely remove the element of bias in exploratory and descriptive studies. The researcher ensured that the research instruments are applied consistently throughout the study without any variations or major amendments as the study progressed. The margin of error should not be large enough to vitiate the validity and reliability of the study. The questions were categorised into themes and the data collection techniques were structured. The researcher did not intend to use unstructured in-depth interviews. Where unstructured interviews were used outside the scope of the sample, it was for purposes of obtaining general opinions on the problem as supportive information for future use by the researcher in his profession as a security practitioner. The use of both closed and open- ended questions enabled cross checking of responses.

Interviews, survey questionnaires and observations are widely accepted methods of collecting information in exploratory and descriptive case studies. The researcher was cautious of the

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dangers of applying his own knowledge and experience in security management as this could have led to biased data collection. It is an unacceptable practice for a researcher to use his or her own opinions in conducting research particularly when presenting findings and recommendations as this will affect the reliability of the study. The researcher pre-tested the research instruments to enhance validity and reliability. This was done through a focus group discussion which provided a good platform for developing the research instruments. Marzyck et al. (2005: 170- 172) also confirm the use of focus group discussions for the preparation of questionnaires. The draft questionnaire was reviewed before final adoption for field work.