# Data Handling and Analysis

## Data organisation

Data handling is tested in the O levels and A levels in the form of different diagrams such as the table diagram. Learn more about the different types of data presentations and how it is used in this short informative article:

Firstly, data is mostly be organised in 3 different ways:

### Frequency table:

Data classified according to the number of occurences. For example, scores of students in a test.

### Dot Diagram:

Using a number of dots to represent the number of times a  particular value occurs. For example, how many students walk pass the MRT station wearing a earphone.

### Stem and Leaf Diagram:

Using the Stem to represent the initial digit in the stem and leaf diagram

Stem represents the number in the tens place

Leaf represents the number in the ones place

A stem with number 7 and leaf with number 4 represents 74.

## Presenting Data

Presenting Data

### Table:

Uses: Tables are versatile for presenting organized data, especially when you have multiple categories, values, or variables to compare. They are excellent for precise numerical data, such as survey responses, scientific observations, and financial data.

Advantages: Tables allow for easy comparison and reference of specific data points. They can accommodate large datasets. They are straightforward and unbiased.

Example: An exam result table that lists students’ names, subjects, and scores.

### Bar Graph:

Use: Bar graphs are effective for comparing different categories or groups and showing the distribution of data. They are suitable for illustrating frequency, percentages, and comparisons.

Advantages: Bar graphs provide a visual representation of data, making it easy to compare values at a glance. They are suitable for both small and large datasets.

Example: A bar graph showing the sales performance of different products in a store.

### Pictogram:

Use: Pictograms use pictures or symbols to represent data. They are engaging and useful for presenting simple, visual information, especially to younger audiences.

Advantages: Pictograms make data more accessible and memorable. They work well for visualizing simple, categorical data.

Example: A pictogram representing the number of students in different school clubs using smiley faces for each club.

### Line Graph:

Use: Line graphs are ideal for displaying trends over time. They connect data points with lines, making them useful for showing changes, fluctuations, and patterns.

Advantages: Line graphs help to identify trends and relationships in time-series data. They are effective for forecasting and prediction.

Example: A line graph representing the temperature variations over a week.

### Pie Chart:

Use: Pie charts are suitable for displaying parts of a whole. They are great for showing the proportion of different categories in a dataset, especially when there are distinct, non-overlapping categories.

Advantages: Pie charts make it easy to visualize the distribution of a whole into its constituent parts. They help in understanding the relationship between categories.

Example: A pie chart illustrating the budget allocation for a project with sections for labor, materials, and overhead.

### Histogram:

Use: Histograms are employed to display the distribution of continuous data or numerical data grouped into intervals or bins. They help analyze the frequency and spread of data.

Advantages: Histograms provide insights into the shape of the data distribution, such as whether it’s normal, skewed, or bimodal. They are crucial in statistics and data analysis.

Example: A histogram representing the ages of participants in a survey, grouped into age brackets.

Each data presentation model has its unique purpose and is selected based on the type of data you want to convey and the message you want to communicate. Understanding when and how to use each type is a valuable skill in data representation and interpretation.