ST3001 Graphical Representation and Descriptive Data

ST3001 Graphical Representation and Descriptive Data

Student Name

Walden University

St3001 Assessment

Professor Name

Date

Describing and Graphing Data

Part One – Determining Variables in a Published Research Paper

Chosen Study: Perming, C., Thurn, Å., Garmy, P., & Einberg, E.-L. (2022). Adolescents’ experience of stress: A focus group interview study with 16-19-year-old students during the COVID-19 pandemic. International Journal of Environmental Research and Public Health, 19(15). https://doi.org/10.3390/ijerph19159114 

• In your own words, summarize the study and explain what it focused on, as if you were describing it to someone unfamiliar with the abstract.

The study titled “Adolescents’ experience of stress: A focus group interview study with 16–19-year-old students during the COVID-19 pandemic” is aimed at exploring the stress among adolescents – young people aged 16 to 19 years. It covered topics about school-related stress, relationship and leisure stress, stress manifestation in adolescents, whether stress affected performance, and student experience of countering stress. In the end, it found that stress among students was governed by a school’s design, high stress levels harm students and lower school performance, and moderate stress had positive impacts such as serving as a motivating factor for students to attain their goals. At the core, it offers insights into the physiological impact of the COVID-19 pandemic on adolescents, informing policies and interventions set to address stress in the demography in time of crisis. 

• What sample was used in the study? Explain your answer and provide supporting evidence from the textbook or other resources.

The study utilized purposive sampling which enabled the researchers/interviewers to select participants strictly based on the research question and the required participant characteristics. According to Perming et al. (2022), the sample population for the study was 41 students [32 females and nine males] at upper secondary schools in southern Sweden. Focusing on such a population enabled them to ensure the study objectives were met and participants who failed to meet its objective were eliminated and not involved at all.

• What population does this sample best represent? Explain your answer and provide supporting evidence from the textbook or other resources.

The sample best represents students aged 16 to 19 years in upper secondary school in southern Sweden. The study aimed at investigating stress among adolescents during the COVID-19 pandemic. Thus, the sample represents adolescents in secondary school, which is the target group and typically aged 16 to 19 years.  

• Specify at least one variable that was analyzed in this study. Classify this variable as quantitative or qualitative. Explain your answer and provide supporting evidence from the textbook or other resources.

Among the variables examined in the study is stress manifestation, which is a qualitative variable. Perming et al. (2022) mention that the adolescents pointed out stress manifested as psychosomatic symptoms as they experienced issues such as headaches, depressive symptoms, body aches, and challenges sleeping. Since the experience of stress calls for categorical data and personal views rather than numeric data to be explained, it comes out as a qualitative variable. The students can only describe their experiences in a subjective manner, ruling out the use of numerical data- quantitative variables.  

• Describe the level of measurement for the variable identified in Section 4. Explain your answer and provide supporting evidence from the textbook or other resources.

The variable stress manifestation is a nominal variable. O’Shaughnessy et al. (2025) state that nominal variables are meant to represent categories without inherent order or ranking. The categories identified with the variable such as headaches and depressive symptoms lack a specific order, ranking, or numerical values associated with them. Thus, they fit the nominal level.

• Determine if the study is overall a quantitative or qualitative study. Provide a justification using a minimum of two important aspects that support the selected study design. Explain your answer and provide supporting evidence from the textbook or other resources.

The study is overall qualitative. This is because it uses interviews to capture the participants’ stress experiences. Perming et al. (2022) state that the study held focus group interviews based on a semi-structured interview guide with open-ended questions. This implies that the collection of numerical data was an aspect of the study. The other aspect supporting its qualitative nature is the adopted analysis method. Perming et al. (2022) point out that Hsieh and Shannon’s conventional qualitative content analysis was utilized. Being an approach that aims at theme and pattern identification within narratives as it derives categories from the provided data, the study was qualitative. Exploration/examination was focused on, not a statistical analysis of stress among students.

Part 2 — Data Analysis

Creating Graphical Displays of Data

The graph used to show the breakdown of smokers and nonsmokers is a pie chart. The chart shows that 48 percent of individuals in the dataset are nonsmokers, while 52 percent are smokers. Hence, there are more nonsmokers than smokers in the dataset. 

Histogram

The histogram shows that the majority of people in the dataset have a BMI between 26 and 30. 

Box Plots

The boxplots include the five numbers from the five-number summary: minimum, Q1, median, Q3, and maximum, which are nicely labeled. It was found that outliers existed in both groups. The box plots show that nonsmokers have a higher BMI than smokers. For the non-smoker BMI, the minimum data point was 18.7 and maximum was 45.9 while for smokers the minimum data point was 18.1 and maximum as 44.2. 

Descriptive Statistics

Comparing Date

• Which group has an BMI that is typically higher? Be sure to write at least one sentence justifying your reasoning including values from the excel output.

Based on the descriptive statistics, the mean BMI for smokers is 28.62 while that of nonsmokers is 29.19. Thus the BMI for nonsmokers is higher. 

• Which group has greater variation in their BMI?  Be sure to write at least one sentence justifying your reasoning including values from the excel output.

Variations in the BMI are shown by standard deviation. Smokers have a standard deviation of 5.0 while nonsmokers standard deviation is 6.11. Nonsmokers therefore have a greater variation implying that their BMI values are more spread out from the mean than of smokers.

• Do you suspect any outliers are present in the BMI for each group? Be sure to justify your reasoning.

Outliers were present in both BMI groups – upper outliers. The non-smokers data points (45.9 and 40.2) were higher than the mean at 29.19. They also had a greater variance. The smokers’ distribution had a data point of 44.2 and two others of 35.0. These were far from the mean of 28.62. Smokers have a skewness of 0.74 while nonsmokers have a skewness of 0.50. This implies that outliers are more present among smokers than nonsmokers. Mazarei et al. (2025) define outliers as data points that significantly deviate from underlying distribution data and they are present when data shows skewness. The skewness of 0.74 shows that the BMI distribution for smokers is moderately skewed and the nonsmoker BMI distribution is approximately symmetric (normal).

References

Mazarei, A., Sousa, R., Mendes-Moreira, J., Molchanov, S., & Ferreira, H. M. (2025). Online boxplot derived outlier detection. International journal of data science and analytics, 19(1), 83-97. https://doi.org/10.1007/s41060-024-00559-0 

O’Shaughnessy, E., Detrinidad, E., Soyer, P., & Lecler, A. (2025). An introductory guide to statistics for the radiologist. Diagnostic and Interventional Imaging, 106(2), 49-52. https://doi.org/10.1016/j.diii.2024.11.003 

Perming, C., Thurn, Å., Garmy, P., & Einberg, E.-L. (2022). Adolescents’ experience of stress: A focus group interview study with 16-19-year-old students during the COVID-19 pandemic. International Journal of Environmental Research and Public Health, 19(15). https://doi.org/10.3390/ijerph19159114