Part 1 Flashcards
Introduction to Statistics Fundamental Concepts Types of Data Levels of Measurement
What is Statistics?
Statistics is the science of collecting, organising, summarising and analysing data to answer questions or provide conclusions.
What are the TWO major concepts of Statistics?
1) Variation (changes/differences in an item)
2) Data (observations gathered to draw conclusions)
What are the TWO main types of Statistics?
1) Descriptive statistics
2) Inferential statistics
Define Descriptive Statistics…
The statistical method used to describe data that has been collected.
Define Inferential Statistics…
The statistical method used to find the characteristics of a population based on a sample.
What are some key features / keywords that can be found in Descriptive Statistics?
Mean / median / mode
Range / variance / standard deviation
Charts / graphs
What are some terms that can be found in Inferential Statistics?
Confidence interval
Margin of error
Define Experimental Unit…
An object about which we collect data. / The individuals or items on which we perform the experiment.
Define Population…
A set of all units we are interested in studying,
Define Parameter…
A specific characteristic of a population.
What is a census?
When every experimental unit of a population is examined, it is called a census.
Define Sample…
A subset of units of a population.
Define Statistic…
A specific characteristic of a sample.
Define Variable…
A characteristic that varies from one objects to another.
How can data be classified according to the source?
1) Primary Data
2) Secondary Data
Define Primary Data…
Data collected by the investigator conducting the research.
Give THREE benefits of having a primary data source to a study.
1) Data is original
2) Data is current and realistic
3) Data is reliable
Give THREE disadvantages of having a primary data source in a study.
1) Data collection requires time and effort
2) Data collection cost is high
3) Trained people are needed to gather data in some cases.
Define Secondary Data…
Data collected by someone else for some other reason/research. / The person performing the data analysis is not the data collecter.
Give THREE advantages of using a secondary data source in a research.
1) Cheaper and faster access to data
2) Saves time and money
3) The direction of the research can be determined easily
Give TWO disadvantages of having a secondary data source in a study.
1) Data may be obsolete
2) Data may not be reliable
Name SIX methods of collecting data.
1) Questionnaires
2) Interviews
3) Designed experiments
4) Registration
5) Survey
6) Published sources
What are the TWO main types of Data?
1) Quantitative Data
2) Qualitative Data
Define Quantitative Variables…
A quantitative variable describes a quantity or measurement where the magnitude is meaningful.
How are Quantitative Variables further classified?
1) Discrete Variables
2) Continuous Variables
Define Discrete Variables…
Variables whose possible values can be listed even if the list continues indefinitely.
(involves a count of something)
Define Continuous Variables…
Variables which can take any value between its minimum and maximum value.
(a measurement)
Give another name for Qualitative Variables
Categorical variables
Give another name for Qualitative Variables
Numerical variables
Name the FOUR Levels of Measurement in order
1) Nominal
2) Ordinal
3) Interval
4) Ratio
Which type of data can be measured on a Nominal or Ordinal scale?
Qualitative data/ Categorical data
Which type of data can be measured on an Interval or Ratio scale?
Quantitative data/ Numerical data
Give TWO characteristics of the Nominal level of measurement.
1) Data consists of names/ labels/ categories only.
2) The data cannot be ranked or ordered.
Give THREE characteristics of the Ordinal level of measurement.
1) The data can be arranged in some order.
2) The precise difference between measurements cannot be determined.
3) The data cannot be used for computations.
Give THREE characteristics of the Interval level of measurement.
1) The intervals of the data is meaningful.
2) The ratios are not meaningful.
3) Data has an arbitrary zero point.
Give TWO characteristics of the Ratio level of measurement.
1) Both the intervals and the ratios of the data are meaningful.
2) Data has an absolute zero point.
Define Qualitative variables
Qualitative variables describe a quality or class where the magnitude of the measurement is not meaningful. (can be numerical/ non-numerical)
