CHAPTER ONE: OVERVIEW AND RATIONALE FOR THE STUDY
4.4 STUDY DESIGN
The present study followed a two-phase methodological framework, as the data collection methods and analysis occurred in specific steps within each phase. Each phase had several objectives and each objective was dependent on the outcomes of the analysis of the results in the preceding objective. The execution of aim one and two of the study was included in Phase 1, while aim three was handled in Phase two of the study.
The design strategy adopted for this study was thus two fold viz. a Descriptive-survey design for aim one and aim two of the study and a Within - participant quasi-experimental design for aim three of the study. The following discussion provides the rationale for the choice of the design for each aim A descriptive-survey design was considered a suitable choice for aim one and aim two of the study because it focused on describing the process involved in the establishment of appropriate criteria relevant to the development of a SRT word list in Zulu and the assessment thereof. Hence, a survey approach and a rating strategy was adopted to realize aim one and two of the study. The descriptive design "describes a situation as it is" in order to gain more information (Leedy & Ormrod, 2005, p. 179). Thus, for aim one and aim two of the study the researcher was concerned with describing the development and assessment of an SRT word list for Zulu. In the process relevant language specific information about the suitability of criteria to be used in the selection of Zulu words was explored.
The overall design for aim three of the study was a within - participant quasi experiment design (Leedy & Ormrod, 2005). This design was suitable, as aim three focused on assessing the application of the developed word list realized in aim one and two of the study. A within -participant design according to Leedy & Ormrod (2005) refers to assessing the participants performance on the basis of two different treatments i.e. the assessment of SRT in Zulu compared to the pure tone average and the assessment of SRT in English compared to the pure tone average. Essentially, the researcher was concerned with observing the potential effects or differences in SRT scores when each word list was used to measure SRT. The within-participant strategy however, was used within a quasi-experimental approach, as all confounding variables could not be controlled for (Leedy & Ormrod, 2005).
Thus, variables that were not controlled for were considered in the interpretation of the results.
While the present study was based on two different approaches, each phase of the study occurred consecutively. The study had several objectives within
each phase, which utilized several methods of data collection and analysis.
This study also required several participants and sources to be considered and these would be presented later. Validity and reliability of results were established within the study, as the various participant choices, data collection methods and analysis methods in the each objective verified the results.
4.4.1 Phases of the study
The study was divided into two phases so as to facilitate data collection.
Phase 1: included aim one and aim two of the study. Each aim was realized through distinct objectives. Aim one of the study included objective one and two. Objective one and two incorporated the criteria for selecting SRT words i.e. identifying bisyllabic Zulu words that were common and ensuring that the words met the criteria of familiarity, phonetic dissimilarity and low tone verb imperatives. Aim two included the assessment of homogeneity of audibility of the words and the acoustic analysis of the words.
Phase 2: involved assessing the application of the developed Zulu list (the product) on a normative clinical population. Each of the phases would be discussed in detail below.
The discussion of each phase is preceded by Figure 4.1 (overleaf), which illustrates the phases and objectives graphically.
Figure 4 . 1 : Process Flowchart: Two-Phase Methodology
PHASE 1
AIM ONE: THE DEVELOPMENT OF THE WORD LIST
Objective 1: identification of
commonly used bisyllabic Zulu words
Participants : Two Zulu language educators and two ZFL interpreters, familiar with ZFL in KZN Method : Identification and categorization of words in terms of criteria (selection of
Bisyllabic words)
Analysis : Descriptive statistics (bar graphs, pie charts, percentage counts) Outcome : 131 Preliminary words selected
Objective2: Selection of words
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Participants : Five linguistic experts of Zulu
Method : Each linguist completed a rating scale to ascertain suitability of the words Analysis : Mean scores and Kendall's w score for inter-rater reliability
Outcome : 58 words selected for aim two of the study
Continued.
AIM TWO: THE ASSESMENT OF THE WORD LIST
&
Objectivel: Homogeneity of audibility
Participants : Thirty normal hearing ZFLS from KZN
Method : Measured the homogeneity with respect to audibility of the 58 words Analysis : Logistic regression analysis
Outcome : 28 words assessed as most homogenous.
Objective 2: Acoustic analysis
Sample : 28 Zulu SRT words
Method : Acoustic Analysis using the computerized speech laboratory Analysis : Descriptive statistics (frequency counts).
Outcome : Pitch contours and energy contour results were obtained.
PHASE 2
AIM 3: APPLICATION OF ZULU SRT WORDS
Objective 1 and 2
Participants : Twenty six normal hearing adult ZFLS from KZN
Method : Administered the SRT Zulu word list and the English SRT wordlist.
Analysis : Pearson r correlation co-efficient
Outcome : Correlation between the SRT values and pure tone averages were calculated