Chapter 2 Flashcards
(21 cards)
Observation
Observation
An observation is a single piece of information that has been collected from one person or one item. It is the result you record after looking at or measuring something in a study. Each observation helps to build the full set of data.
Measurement
Measurement
A measurement is the value or amount you get when you use a tool or method to find out how much, how long, or how heavy something is. It gives a number that can be used to compare or analyse things. Measurements are usually taken using standard units like metres or kilograms.
Variable
Variable
A variable is something that can change or vary from one person or thing to another. It is the feature or quality that you are studying, such as age, height, or colour. Each variable can take on different values depending on what you observe or measure.
Data
Data
Data is a collection of facts, values, or information gathered from observations or measurements. It is used to study patterns, make decisions, or answer questions. Data can be written as numbers, words, or codes.
Associated
Associated
Two things are associated when they seem to change in a connected way. If one thing happens more often when the other happens, we say they are associated. This does not always mean that one causes the other.
Non-numerical
Non-numerical
Non-numerical means something that is not shown or described using numbers. It could be a word, a label, a colour, or a type. You cannot count or measure it with a number.
Numerical
Numerical
Numerical means something that is written or described using numbers. It can be counted or measured, such as how many, how long, or how far. Numerical values can be used in calculations.
Qualitative variable
Qualitative variable
A qualitative variable is a variable that describes a quality, type, or group. It tells us what kind something is, not how much. Examples include hair colour, type of fruit, or name of a city.
Quantitative variable
Quantitative variable
A quantitative variable is a variable that describes an amount or quantity using numbers. It tells us how much, how many, or how often. Examples include temperature, weight, or number of people.
Comparison between qualitative and quantitative variables
Comparison between qualitative and quantitative variables
A qualitative variable shows what type or kind something is, while a quantitative variable shows how much or how many. Qualitative variables use words or labels, but quantitative variables use numbers. You describe categories with qualitative data, but you can do calculations with quantitative data.
Qualitative (general meaning)
Qualitative (general meaning)
‘Qualitative’ means something that is described using words or labels rather than numbers. It tells us about the kind, type, or quality of something, like colour, shape, or feeling. You cannot measure it with a number, but you can describe or sort it into groups.
Qualitative (in the context of mass)
Qualitative (in the context of mass)
Mass itself is not qualitative because it is measured using numbers. However, a qualitative description related to mass might say something is “heavy” or “light” without giving a number. This kind of description gives a general idea but not an exact value.
Quantitative (general meaning)
Quantitative (general meaning)
‘Quantitative’ means something that is described or measured using numbers. It tells us how much, how many, or how often something happens. Quantitative descriptions always use values that can be compared, added, or used in calculations.
Quantitative (in the context of mass)
Quantitative (in the context of mass)
When we say something has a mass of 2.5 kilograms, that is a quantitative measurement. It gives us an exact amount using numbers, which we can use to compare with other values, like checking if one object is heavier than another.
Continuous data
Continuous data
Continuous data can take any value within a certain range and is usually measured, not counted. It includes things like weight, height, or time, which can have decimals and don’t jump from one number to the next. You can always make the measurement more exact by using smaller units.
10 Discrete Variable Examples
（These are counted in whole numbers. You cannot have values in between.）
- Number of children in a family
- Number of goals scored in a football match
- Number of pages in a book
- Number of pets
- Number of pencils in a box
- Number of teachers in a school
- Number of cars in a garage
- Number of phone calls in a day
- Number of lightbulbs in a house
- Number of socks in a drawer
Discrete data
Discrete data
Discrete data is made up of separate, individual values that you can count. It can only take specific whole numbers, like 1, 2, 3, and not values in between. Examples include the number of books, people, or goals in a game.
Give 10 Qualitative Variables examples (that describe qualities, types, or categories using words or labels.)
- Hair colour
- Nationality
- Type of smartphone
- Eye colour
- Preferred language
- Type of cuisine (e.g. Italian, Indian)
- Brand of shoes
- Genre of music
- Type of pet
- Car brand
Give 10 Quantitative Variable Examples
(These are variables that describe quantities, always using numbers.)
- Height in centimetres
- Number of pens
- Temperature in degrees Celsius
- Mass in kilograms
- Time in seconds
- Distance in miles
- Age in years
- Number of siblings
- Shoe size (as a number)
- Exam score out of 100
Frequency table
A frequency table is a way of organising data to show how often each value or group of values appears in a data set.
The word ‘frequency’ refers to the number of times a particular value occurs, and it is often represented by the symbol ‘f’ or ‘F’.
Frequency tables help summarise raw data in a clear and structured form, allowing patterns and trends to be identified quickly.
They are especially useful in statistics when analysing how often different outcomes occur.
Frequency tables can be used with both individual data values (ungrouped data) and with data values that have been grouped into intervals (grouped data).
10 Continuous Variable Examples
(These are measured, and they can take on any value in a range (even with decimals).)
- Height of a person in metres
- Time taken to walk to school
- Temperature in a classroom
- Weight of a newborn baby
- Distance run in kilometres
- Volume of water in a bottle
- Length of a pencil
- Width of a table
- Speed of a car
- Mass of an orange
