Personal Selling As An Effective Promotional Tool In Marketing Of Industrial Goods
[A CASE STUDY OF NNPC, ILORIN]

3.3    SOURCE OF DATA COLLECTION
    Data can be collected from two major source namely primary and secondary sources.
    Primary source is a way of collecting data, information on research work form the following sources.
Questionnaire
Interview
Observation
Experiment.
    All this were used for collecting data for study.
Secondary data: these are made or existing information which are useful for the purpose of this research work.
    These include organization records, text books, internet, and journals.
3.3.1    BOTH PRIMARY AND SECONDARY METHOD OF DATA COLLECTION
Both were employed for this study, questionnaire was administered to the staff of NNPC in Ilorin especially those in the marketing and sales department, interview and personal observation were also used to study the sample population.
3.4    DATA PRESENTATION AND ANALYSIS TECHNIQUES    This chapter is aimed at presenting data collection analysis and making proper presentation with view to ensuring that the objective of research are accomplished.
The researcher was able to gather some information through the use or questionnaire and personal interview. These were administered in the case study in order to facilitate easier distribution of questionnaire. A total number of 200 (two hundred) questionnaire were administered and 150 (one hundred and fifty) out it were killed properly by the respondents and collected which serve as a basic for statistical analysis. The data were presented in table using ratios and percentages. The data were analyzed using the chi-square method.
3.5    INSTRUMENTATION
    Generally, there are many methods through which data can be collected. The most prominent are among the many methods is the survey method which includes the use of questionnaire and personal interview which were used for this research. These were to collect the primary data the questionnaire was designed for the personal selling as a promotional tool in marketing of industrial goods, NNPC Nigeria Ltd within Ilorin and some other state within Nigeria.
    While personal interview was employed to elicit information from the staff of NNPC particularly in the marketing section.
    The secondary source of collecting data are employed by gathering come ready made information from the library of NNPC by going through the literature like magazine, Newspapers and text books.
3.6    VALIDITY OF INSTRUMENT
    According to Ogene (2003), validity of measuring instrument. Validity of measuring instrument is then defined as the ability of the instrument which measure correct time. Otherwise, it is not a valid chronological instrument.
    Also, a least is valid when the result obtained from it services the purpose for which it is intentend.
    Validity could be defined as the truth fullness of in instrument.
    A research design may be said to be valid if it enable a researcher elicit the correct responses from the sample subjects, otherwise, it is a faulty design and may lead to current findings. The concepts of validity can be applied in two areas of the research validity of measurement (2003).
    By validity the behavioral scientist means that the data must be un-biased are relevant to the peculiarities being measured (Green, Tull and Albavin 1992).
    We can thus, view the validity of a scaling procedure (or measuring instrument generally) in terms of freedom from systematic error: that is its ability of reflect “either among individual at point in time or within a sample individual over time.