Basic Concepts of Statistics Flashcards
A science that involves the efficient use of numerical data relating to groups of individuals.
Statistics
A science of collecting, organizing, presenting, analyzing, and interpreting numerical data.
Statistics
To provide an overview of the information gathered.
Descriptive Statistics
Describes information through numerical measurements, charts, graphs, and tables.
Descriptive Statistics
Takes results obtained from a sample, extend them to the population, and measures the reliability of the results.
Inferential Statistics
Large amount of data.
Population
The set of all possible values of variables where making a census or a complete enumeration of it would be impractical or impossible.
Population
Subset of population
Sample
Calculated from the samples to make conclusions about the population.
Statistics
Opposite of quantitative variables as it describes certain types of information.
Qualitative Variables
Examples are: Name, Gender, Address, Religion, Name of School, Subject, and Program.
Qualitative Variables
Measures or identifies population or sample based on a numerical scale.
Quantitative Variables
Can be analyzed using statistical methods.
Quantitative Variables
Variable that can be assume finite, or, at most, countably infinite number of values, usually measured by counting or enumeration.
Discrete Variable
Example: Number of children in a family, Number of students in a class, Maximum number of adults that can fit in a car, etc.
Discrete Variable
Variable that can assume infinitely many values corresponding to a line interval.
Continuous Variable
Example: Time, Temperature, Weight, Height, Speed, etc.
Continuous Variable
Scales of Measurement
Levels of Measurement
Ways in which variables/quantities are defined or categorized.
Levels of Measurement
Numbers serve only as labels or tags for identifying and classifying objects.
Nominal
A ranking scale in which numbers (ranks) are assigned to objects to indicate the relative extent to which the objects possess some characteristics.
Ordinal
Represents an equal distance between the values in the characteristic being measured.
Interval
Possesses all the properties of nominal, ordinal, and interval scale and, in addition, an absolute zero point.
Ratio
Process of gathering and measuring information on variables of interest in an established systematic fashion.
Data Collection
Information collected by the person who is doing the research.
Primary Data
Any material that has been collected from published records.
Secondary Data
When a researcher has a direct contact with the interviewee.
Direct Personal Interviews
Suitable when there is a need to collect in-depth information on people’s opinions, thoughts, experiences, and feelings.
Direct Personal Interviews
Advantages of Direct Personal Interviews
In-depth information can be collected.
Non-response and Response biased can be detected.
Samples can be controlled.
Disadvantages of Direct Personal Interviews
More time consuming
Expensive
Interviewer may be biased
Situation where a respondent gives an inaccurate or false answer.
Response Bias
Occurs when people are unwilling or unable to respond to a survey due to factors that makes them differ greatly from people who respond.
Non-response Bias
Useful when there is a large number of respondents.
Indirect/Questionnaire Method
Involves sourcing and accessing existing data that were originally collected for the purpose of the study.
Indirect/Questionnaire Method
Key Design Principles of a Good Questionnaire
As short as possible
Decide the type of questionnaire
Write the questions properly
Order the questions properly
Write an introduction
Write special instructions
Translate questions if necessary
Pretest the questionnaire
Respondents are allowed to answer in an open text format.
Open-ended Questionnaire
Advantages of Open-ended Questionnaire
More detailed answers
Could reveal additional insights
Disadvantages of Open-ended Questionnaire
Difficult to encode, tabulate, and analyze
Low response rate
Respondent has to be articulate
Respondent could feel threatened
Respondents are asked to choose from a distinct set of pre-defined responses such as “yes” or “no” among a set of multiple-choice questions.
Closed-ended Questionnaire
Advantages of Open-ended Questionnaire
Easy to encode and tabulate
Easy to understand
Enables inter-study comparisons
Saves time and money
High response rate
Disadvantages of Open-ended Questionnaire
Could frustrate respondents
Potentially biased response sets
Difficult or impossible to detect if the respondent truly understood the question
A group interview of approximately six to twelve people who share similar characteristics or common interests.
Focus Group
He guides the group based on a predetermined set of topics.
Facilitator
Advantages of Focus Group
Less costly compared to interviews
Takes lesser time
Disadvantage of Focus Group
Response bias is a problem (participant may be subjective to what people will think about sharing a sincere opinion)
A method of collecting data where there is a direct human intervention on the conditions that may affect the values of the variable of interest.
Experiment
Usually controlled by the researcher, who determines which subject is used, how they are grouped, and the treatment they receive.
Experiment
Advantages of Experiment
Usually objective since the data is the results of the process
Non-response bias can be eliminated
Disadvantages of Experiment
Incorrect data may be recorded due to human error
Expensive
Method of collecting data on the phenomenon of interest by recording the observations made about the phenomenon as it actually happens.
Observation
Usually systematically planned and subjected to checks and controls.
Observation
Advantages of Observation
Data is objective
Data is not affected by past or future events
Disadvantages of Observation
Limited information
Expensive
Data that has already been collected and is available from other sources.
Secondary Data
Less costly and is easier to obtain than primary data.
Secondary Data
Advantages of Secondary Data
Generates new insights from previous analyses of primary data
Provides a basis for comparison for he data collected
Economical
Time-saving
Disadvantages of Secondary Data
Accuracy is questionable
Not all secondary data is readily available or inexpensive
Data may not be appropriate to the needs of the user
Sources of Secondary Data
Published report on newspaper and periodicals
Financial data reported in annual reports
Records maintained by the institution
Internal reports of the government
It is usually very reliable. Data from these sources are usually more political, economic, and educational.
Published report on newspaper and periodicals
An in-depth or comprehensive overview of a business’ achievement and key metrics for a specific year.
Annual Reports
Mostly used for the company’s employees, customer, suppliers, investors, and community at large.
Financial Reports
It can be used to evaluate the company’s financial health and earnings potential.
Financial data reported in annual reports
Created to document anything that is part of an institution.
Institutional Records
Information is managed to support the institution’s present and future regulatory, legal, environmental, and operational requirements.
Records maintained by the institution
These are very important and authentic source of secondary data.
Government Reports
These are collected to aid proper planning, allocation of funds, and prioritizing of projects.
Internal reports of the government
Consequences from Improperly Collected Data
Inability to answer research questions accurately
Inability to repeat and validate the study
Distorted findings resulting in wasted resources
Misleading other researchers to pursue fruitless avenues of investigation
Compromising decisions for public policy
Causing harm to human participants and animal subjects
