Critical Analysis
The article by Kovacic (2005) presents a study of voice education in teacher training. In the study, the author focused on voice and voice care knowledge in teacher-training students. The study is important to educational research, as it indicates gaps in voice knowledge and voice care, which could potentially affect learning and teaching outcomes. The author also explains that voice education can assist in preventing and treating voice disorders in teachers, thus allowing them to use their voice more efficiently. The article provides a wide range of background information that highlights the importance of research and voice education in general. The key result of the study was that it indicated the lack of sufficient knowledge about the voice and voice care in teacher-training students considered as part of the research.
The primary goal of this essay is to offer a critical analysis of the study and the report provided by Kovacic (2005). The critical analysis includes a detailed examination of the work and allows indicating its strengths and weaknesses. In addition, the findings offered by the critical analysis can inform further research on the topic by explaining gaps to be addressed in future studies. The primary focus of the analysis will be on the methodology of the study, although a full overview will also be provided to ensure a comprehensive investigation. The work will largely rely on books by Cohen, Manion, and Morrison (2007) and Porte (2002) to inform the evaluation of methods. Using an established analytical framework, the essay will identify the key achievements and limitations of the research, as well as review possible options for improvement, thus offering a thorough evaluation of the study.
Overview
The author begins with an introduction to the use of voice, and how voice skills can be useful to people of various professions, including lawyers, politicians, presenters, and others. Kovacic (2005) explains that, although teachers are not normally considered to be professional voice users, they can still benefit from voice skills. Moreover, the author describes the issue of voice disorders, explaining how they can be prevented using voice education. Kovacic (2005) states that the key aim of the study is to determine the level of voice and voice care awareness among teacher-training students enrolled at the University of Zagreb in Croatia.
The study used a quantitative methodology with a questionnaire as a key tool for data collection. The study sample was divided into teacher-training students (184) and the control group of mixed-subject students (143). The questionnaire was a 20-item, true-false survey, which was completed by both the teacher-training students and the control group in order to compare the results between the two groups. The questionnaire included statements about various factors influencing voice, such as smoking, hormonal changes, screaming, and more. The answers were assessed for their correctness, with right answers scoring 1 point and wrong answers scoring 0 points each. After the initial assessment, the results were processed to obtain descriptive data and then analysed using canonical discriminant analysis.
The key finding of the study was that the teacher-training students’ knowledge about the voice was only slightly better than that of other students (52% and 48% correct answers respectively). Thus, it is evident that the education program used in teacher-training does not provide sufficient education on voice use, which would benefit students in their future career. The author also provides an overview of high-scoring items across each group. For instance, the teacher-training students achieved excellent results in Smoking, Scream, Genetics, and Hoars 1 items, whereas the students of other professions only achieved high scores in Smoking and Genetics (Kovacic, 2005). The discriminant function analysis also showed that the experimental group showed the most significant increase in knowledge compared to the control group on items Scream, Whisper, Laughing, Noise, and Fatigue (Kovacic, 2005). Thus, one of the main conclusions that were reached as part of the study is that the voice knowledge of teacher-training students compared to students of other professions is better on some items. This indicates that, although the average scores are similar in the two groups, teacher-training students possess a more comprehensive knowledge of voice and voice disorders. However, their knowledge is still insufficient to benefit them in further life, which is why a thorough approach to voice education of teacher-training students is required (Kovacic, 2005).
Analysis of Methodology
Although the study achieved significant results, offering an insight into the level of voice knowledge in teacher-training students, it had some limitations with regards to its methodology and design. As explained by Cohen et al. (2007), the method is among the most important factors affecting the reliability and validity of a study, which is why any methodological failures can significantly impair the quality of research. In the case of Kovacic (2005), the key limitation of the author’s methods is the sampling strategy used.
Sampling
Sampling strategy has a significant influence on the quality of a scientific study (Cohen et al., 2007). Furthermore, sampling has a direct effect on the possibility of generalising the results to other populations. In order to ensure a high quality of research, it is crucial for authors to choose an appropriate sample method, size, and composition of the sample (Cohen et al., 2007).
Sampling method
The author does not mention the sampling method used for the study. However, based on the fact that the sample featured a large number of students from one university suggests that either purposive or convenience sampling were used. Both of these strategies are non-probability sampling methods. As noted by Cohen et al. (2007), non-probability sampling methods generally impair the representativeness of the sample, which affects the possibility of generalising the results. In addition, non-probability sampling presents a greater risk of bias, which also affects the quality of results and conclusions (Cohen et al., 2007). On the whole, the sampling methodology used affects the quality of the study in a negative way. Using probability sampling, on the other hand, would allow the author to avoid bias and to ensure that the results are representative.
Sample size
According to Cohen et al. (2007), decisions about sample size are made based on the population size, the number of variables included in the study, sampling method, required representativeness, and more. In addition, the authors insist that allowances for attrition and non-response have to be made to avoid reduction of the sample size due to these factors (Cohen et al., 2007). The author of the present study does not provide a justification for choosing the overall sample size of 327 students. Also, there is no information about the response rate for the questionnaire and other factors that could have affected the size of the sample throughout the study. Based on the information that is provided by Kovacic (2005), the number of responses obtained is enough to draw conclusions; however, it might not be enough to generalise the findings to other populations, including other universities and countries. Thus, the results obtained are only true for the students of the University of Zagreb and cannot be extended to other teacher-training student populations. This impairs the quality of the study, reducing the proposed impact of the findings on education and practice.
Composition of the sample
The composition of the sample refers to variables such as age, gender, profession, and other factors that can affect the results obtained from participants. In the case of Kovacic (2005), the age composition of the sample is rather even, with both the experimental and the control group averaging 22 years. However, the standard deviation for the age of the control group was much higher, which means that the age distribution was more significant. The gender composition was also uneven, with few males in the control group (Kovacic, 2005). The age and gender composition of the two samples could have affected the results, thus creating a significant possibility of bias. The author fails to address the sample characteristics or provide inclusion and exclusion criteria, which affects the quality of research.
Data Collection
The data collection method is among the primary characteristics of every research design. The data collection method depends on the methodology (qualitative or quantitative), sample size, the number of variables, and other factors (Porte, 2002). For example, semi-structured interviews are widely used in qualitative studies with a rather limited number of participants. Questionnaires, on the other hand, are usually used in quantitative research, as they are usually fully structured and can be completed in a short time, and thus allow including more participants in the study. In addition, questionnaires are easier to process and analyse. Thus, I feel that the choice of a data collection method in Kovacic (2005) is fully justified. Indeed, by using a survey, the author was able to obtain more responses and assess them. The design of the questionnaire also allowed to address multiple items and compare knowledge levels across the two samples.
The study included a wide variety of items, which allowed the researcher to cover various aspects of voice knowledge. However, there were some statements that generally do not require the respondent to have specific voice education to respond correctly. For instance, two of the statements examined in the questionnaire were “Smoking affects voice” and “Screaming can harm the voice” (Kovacic, 2005). The negative effect of smoking and screaming on the voice can be considered common knowledge. In order to better understand the effect of education programs on voice knowledge, it would be better for the authors to include more specific items covered in voice education programs. Nevertheless, the questionnaire composed by the authors offers appropriate coverage of the topics and is thus relevant to the aim and methodology of the research.
The other aspect of the questionnaire design that raises some concerns is its structure. The authors used true-false statements to evaluate students’ knowledge of various factors affecting the voice. Such structure is rarely used in questionnaires and is more characteristic of the test data collection method (Cohen et al., 2007). Cohen et al. (2007) also explain that fully structured questionnaires limit the participants’ opportunities for reflection and justification of their answers. Although the structure chosen by the author is efficient, it might have been preferable to allow participants to provide comments to their responses. This would have increased the depth of the analysis, allowing the study to identify sources of voice knowledge.
Data Analysis
The three key analysis methods used by the author are descriptive statistics, exploratory data analysis, and canonical discriminant analysis. Although the first two tools are appropriate to the design and purpose of the research, the canonical discriminant analysis is not among the quantitative data analysis tools described by Cohen et al. (2007) as appropriate and reliable. On the whole, there are no significant concerns with relation to the data analysis procedures used by the authors. However, using other methods to examine the correlation between being a teacher-training student and having a better knowledge of factors affecting voice would have benefited the study.
Descriptive Statistics
Descriptive statistics are widely used in quantitative and mixed-method studies to present the overall information on responses and respondents. As stated by Porte (2002), descriptive statistics allows summarising the data in a concise and understandable manner. Descriptive statistics “convey information about the most typical values obtained and how these are spread out across the data sample” (Porte, 2002, p. 234). The author uses descriptive statistics correctly, providing a useful overview of the responses obtained from participants. The table presented by Kovacic (2007) reflects mean age, standard deviation, minimum age, maximum age, and gender of the participants from both groups, thus providing an overview of the samples’ composition.
Exploratory data analysis
Exploratory data analysis is among the key quantitative analysis tools described by Cohen et al. (2007). As noted by the authors, exploratory data analysis includes percentages, frequencies, bar charts, graphs, and other visuals to represent the overall direction of the data obtained (Cohen et al., 2007). The author of the study chose to include a table representing frequencies and percentages of responses gathered from the two sample groups. The table offers a useful description of the answers, allowing to draw a comparison between the experimental sample and the control group. The table presents both the number of the correct/”I don’t know”/incorrect answers and their percentage shares from the total number of responses on each item, which also aids in the comparison. Overall, the exploratory data analysis method benefits the study by presenting the results in a detailed yet clear manner, which contributes to the quality of research and analysis.
Canonical discriminant analysis
The canonical discriminant analysis used by the author to analyse the findings is not explored by Cohen et al. (2007) or by Porte (2002), which means that it is not a popular method of quantitative data analysis. The method allowed the author to “determine the extent to which questionnaire items were able to distinguish the knowledge on voice care between the experimental and control samples” (Kovacic, 2005). Nevertheless, I believe that the same result could have been achieved if the author used one of the quantitative data analysis tools suggested by Cohen et al. (2007), such as one- or two-tailed tests or correlation analysis. Using these methods would have improved the reliability of the study and enhanced its scope, as they are considered to be appropriate to the analysis of quantitative data (Cohen et al., 2007).
Discussion and Limitations
On the whole, the study has managed to achieve its key goal, which was “to investigate the knowledge about the voice and voice care among teacher-training students from the University of Zagreb in Croatia” (Kovacic, 2005, p. 89). The design of the study allowed to obtain a significant sample and to draw conclusions based on the responses to the questionnaire. The data collection and analysis methods used by the author was reliable and appropriate to the design of the research, which is also important as it ensures the validity of results. Nevertheless, there were also some significant limitations to the methodology used by the author.
Sampling
As shown above, the sampling methodology used by the author was rather weak. According to Cohen et al. (2007) choosing an incorrect or inappropriate sampling methodology results in the sample being unrepresentative of the wider population. Although the sample size used in the study was sufficient to fulfil its goals, the author used convenience sampling, which increases the risk of bias in the results. In addition, the author focused on the students of one university in Croatia. Although such scope is part of the author’s goal, it still impairs the possibility of generalising results to other populations, which reduces the quality of the study.
Improving the sampling technique would have helped the author to ensure that the results of the study can be generalised to other populations of teacher-training students. As it is, the study provides conclusive information on the levels of voice and voice care knowledge in a single university. To improve the depth and scope of the study, as well as to allow for the generalisation of the results, it would be crucial to extend the research to other universities and other countries.
Data Analysis
Another possible limitation of the study is the use of canonical discriminant analysis in data analysis. Although the author applies the tool successfully, no explanation or justification is provided for the use of the tool. Hence, I believe that similar information could have been obtained through the use of more popular, proven tools for quantitative data analysis. Both Porte (2002) and Cohen et al. (2007) stress the importance of choosing reliable analytical tools in ensuring the validity and reliability of research. Therefore, by using a tool that is not considered to be among the key techniques of quantitative data analysis, the author missed an opportunity to improve the quality of the study.
Presentation
Despite the two major limitations explored above, I believe that the main weakness of the author’s research is the presentation. The article by Kovacic (2005) provides very limited information about the study. For instance, there is no description of the sampling method used or the rationale for items and the questionnaire design. Apart from constricting the critical analysis of the study, this also reduces its quality. The author provides no justification for the use of data collection and analysis methods shown in the study, which allows questioning their relevance to the present research. Although Cohen et al. (2007) and Porte (2002) do not stipulate the importance of the write-up in promoting the study’s quality, both sources stress the need for ensuring the relevance of methods to the study’s scope and goals.
In addition, the author fails to review the steps taken to ensure the validity and reliability of research. Cohen et al. (2007) explain that validity and reliability are among the key factors influencing the quality of research. They also discuss the importance of planning the study carefully in order to avoid bias and ensure coherency (Cohen et al., 2007). The author’s choice not to present evidence of addressing validity and reliability concerns thus reduces the value of the study’s outcomes and lowers its quality. Furthermore, Kovacic (2005) offers no description of the stages of the planning process, including the development of the questionnaire, which achieves the same effect.
Finally, Kovacic (2005) does not address ethical issues associated with the sampling and data collection methods used. There is no evidence that the author obtained informed consent from the participants or evaluated the methodology for its adherence to research ethics codes. Cohen et al. (2007) note that ensuring ethical conduct of the study is important, as it helps to avoid bias and promote transparency, while at the same time increasing the value of research.
Conclusion
Overall, the methods used by Kovacic (2005) have significant limitations, which significantly impairs the quality of research produced. For instance, the sampling method used does not allow generalising the findings to other populations of teacher-training students, thus limiting the value of the study. One of the most important weaknesses of the study is the write-up, which provides very few notes on the methodology of the research, thus affecting the present analysis. In order to ensure a better quality of research, it would be crucial for the author to consider expanding the sample and choosing different data analysis tools, as well as to provide a solid justification of the methods used.
The present critical review provides a thorough overview of the methodology used in the study. However, the analysis was limited by the lack of information about the author’s methods. Also, the analysis focused on the methodology of the chosen study and did not reflect on the findings and conclusions drawn by the author. To improve the depth and quality of analysis, it would be useful to consider other factors affecting the quality of the study, such as the theoretical background, discussion of results, and the validity of conclusions.
References
Cohen, L., Manion, L., & Morrison, K. (2007). Research methods in education (6th ed.). London, UK: Routledge.
Kovacic, G. (2005). Voice education in teacher training: an investigation into the knowledge about the voice and voice care in teacher‐training students. Journal of Education for Teaching, 31(2), 87-97.
Porte, G. K. (2002). Appraising research in second language learning: A practical approach to critical analysis of quantitative research. Amsterdam, Netherlands: John Benjamins.