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Questions and Answers
What is a notable advantage of using an interview schedule?
Which statement correctly describes a limitation of the observation method?
What is a major advantage of the experimental method?
Why might interview schedules be seen as more costly?
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Which advantage does observation provide that interviews do not?
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Which of the following is NOT a reason for collecting data?
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Which type of data is collected firsthand by the investigator?
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Which factor is NOT considered when checking the quality of secondary data?
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What characteristic of statistical data refers to the closeness of measurement to its true value?
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Which data collection method utilizes a structured set of questions for responses?
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Which of the following is a desired characteristic of statistical data?
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What is a critical component to validate the use of secondary data?
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Which method is NOT typically used for collecting primary data?
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What is an example of sampling 'with' replacement?
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What is a key characteristic of sampling 'without' replacement?
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What type of graph is best suited for showing trends or changes over time?
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Which term best defines the difference between sampling error and sampling bias?
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What best describes the snowball method of sampling?
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Which graph is most appropriate for displaying the frequency distribution of a continuous variable?
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What is the primary function of a scatterplot?
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Which of the following is NOT considered a type of data presentation in descriptive statistics?
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Which graph is NOT suitable for displaying qualitative data?
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What is the primary purpose of descriptive statistics?
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Which type of graph is generally least effective for displaying categorical data?
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What type of graph should be used when comparing the absolute frequencies of different categories?
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Which graph is recommended when the number of categories is small (6 or fewer)?
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What does population parameters refer to in sampling?
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In a frequency polygon, what does the graph typically represent?
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Which type of graph is best for showing the correlation data of two quantitative variables?
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What is the calculated interval (i) when R is 88 and K is 7?
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What should be the upper limit of the lowest class interval if the lower limit is 23?
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When establishing class intervals, how is the lower limit of the next interval determined?
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What condition must be met for the highest class interval?
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If the lowest score is 10, what is the first lower limit of the succeeding class interval after adding the computed interval?
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How should frequencies be recorded according to the rules provided?
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What should be the total of frequencies when properly counted?
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What is the impact of adding another class interval after reaching the interval that includes the highest score?
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Study Notes
Data and Its Importance
- Data refers to measurements collected from response variables across a sample.
- Example: DMFT rates of 42 subjects highlight the significance of proper data collection.
- Collecting data facilitates reliable decision-making, planning, resource allocation, and prioritization.
Types of Data
- Primary Data: Collected firsthand by the investigator; original source intended for analysis.
- Secondary Data: Existing data previously collected; must be verified for accuracy and validity.
Quality Assessment of Secondary Data
- Conditions and purpose of data collection should be evaluated.
- Reliability of collectors or sources can impact data quality.
- Data must be relevant to current research questions.
Desired Characteristics of Statistical Data
- Timeliness: Data should be current and up-to-date.
- Completeness: All necessary data should be present.
- Accuracy: Measurements should closely align with true values.
- Precision: Data should produce consistent results upon repeatability.
Methods of Data Collection
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Primary Data Collection Methods:
- Questionnaire: Self-administered with standardized questions.
- Interview Schedule: Engages respondents through guided questions; beneficial for diverse respondents.
- Observation: Employed when informants cannot provide data; relies on concise records rather than extensive questioning.
- Experimental Method: Controls variables to understand outcomes; most effective for data collection.
Advantages and Disadvantages of Methods
- Questionnaire Advantages: Efficient, standardized, less time-consuming.
- Interview Advantages: High response rate, ability to clarify questions, observe respondent behavior.
- Observation Advantages: Provides firsthand accounts, effective for non-verbal subjects.
- Experimental Method Advantages: Controlled conditions yield reliable results, fewer subjects needed.
Limitations of Methods
- Interviews: Higher costs, potential bias from the interviewer, and time constraints.
- Observation: Limited to the observed timeframe, cannot access inner feelings.
Sampling Concepts
- Understanding sampling methods is essential for identifying groups:
- Sampling with Replacement: Replacing subjects after selection; allows repetition.
- Sampling without Replacement: Subjects are not replaced once chosen.
- Sampling Error: Variation in sample results compared to the population.
- Sampling Bias: Systematic errors due to non-random selection.
- Snowball Sampling: Participants recruit other participants.
- Fishbowl Method: Random selection from a pool.
- Random Sampling: Every member has an equal chance of selection.
- Non-Random Sampling: Subjects are chosen based on non-random criteria.
Descriptive Statistics
- Focuses on summarizing data into meaningful information.
- Types of data presentation:
- Textual: Narrative summaries ideal for small data sets.
- Tabular: Structured tables for efficient data presentation.
- Graphical: Visual aids to represent data trends and comparisons.
- Numerical: Includes measures of central tendency and dispersion.
Types of Graphs
- Bar Graph: Compares absolute or relative frequencies.
- Pie Chart: Illustrates composition of categories (limited to ≤6).
- Histogram: Displays frequency distribution of continuous variables.
- Line Graph: Shows data trends over time.
- Scatterplot: Examines correlation between two quantitative variables.
Data Presentation Guidelines
- Summarize and round intervals in frequency distributions.
- Ensure class intervals encompass both lowest and highest scores.
- Maintain uniformity in class widths and capture accurate tallies in frequency counts.
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Description
Explore the significance of data collection and its types, including primary and secondary data. Understand key characteristics of reliable statistical data, such as accuracy and timeliness, to enhance your decision-making and research outcomes. This quiz covers essential concepts related to data and its importance in various fields.