Study Notes
Handling data involves planning, collecting, processing, presenting, and interpreting data, as well as understanding probability.
- Qualitative Data — data that can only be written in words, not numbers. Example: The colors of cars in a car park.
- Quantitative Data — data that can be written in numbers. Example: The heights of children.
- Discrete Data — numerical data that cannot be shown in decimals. Example: The number of children in a classroom.
- Continuous Data — numerical data that can be shown in decimals. Example: The weights of 10 babies.
- Primary Data — data collected from the original source for a specific purpose. Example: Surveying students about the school canteen service.
- Secondary Data — data not originally collected by a group for a specific purpose. Example: Using national statistics to find the average cost of cars.
- Mode — the data point that occurs most frequently in a frequency table. Example: In a table, if marks 2 and 3 have the highest frequency, the modes are 2 and 3.
- Mean — the sum of all data divided by the number of items. Example: The mean of marks obtained by players in a game.
- Median — the middle number in ordered data. Example: The median of 50 carrot lengths grouped in intervals.
- Probability — how likely something is to happen. Example: The probability of a coin landing heads is 1/2.
Exam Tips
Key Definitions to Remember
- Qualitative Data: Data in words
- Quantitative Data: Data in numbers
- Discrete Data: Numerical data without decimals
- Continuous Data: Numerical data with decimals
- Primary Data: Data collected for a specific purpose
- Secondary Data: Data not originally collected for a specific purpose
- Mode: Most frequent data point
- Mean: Average of data
- Median: Middle value in ordered data
- Probability: Likelihood of an event
Common Confusions
- Confusing qualitative data with quantitative data
- Misunderstanding the difference between discrete and continuous data
- Mixing up primary and secondary data sources
Typical Exam Questions
- What is the mode of this data set? The mode is the most frequent number.
- How do you calculate the mean from a frequency table? Add all data values and divide by the number of items.
- What is the probability of rolling a 4 on a die? The probability is 1/6.
What Examiners Usually Test
- Ability to distinguish between different types of data
- Calculating mean, median, and mode from data
- Understanding and calculating probabilities