Information is data that has been processed, organized, and structured to be meaningful and useful for decision-making. In data science, information is the output we derive from analyzing raw data.
Data → Processing → Information
For example, a list of student test scores (data) becomes information when we calculate the class average, identify the highest scorer, or visualize score distributions in a chart.
Experimental design is the process of planning how to collect and analyze data to answer a specific question or test a hypothesis. A well-designed experiment produces reliable, valid results.
| Component | Description |
|---|---|
| Hypothesis | A testable prediction about the relationship between variables |
| Independent Variable | The variable deliberately changed/manipulated by the researcher |
| Dependent Variable | The variable measured to observe the effect of the independent variable |
| Controlled Variables | All other variables kept constant to ensure a fair test |
| Sample Size | The number of observations; larger samples produce more reliable results |
| Data Collection Method | How data will be gathered (surveys, sensors, observation, etc.) |
Question: Does the amount of sleep affect exam performance?
Summary statistics are numerical values that describe the key features of a dataset. They allow us to understand large amounts of data quickly.
| Statistic | Definition | Example (Dataset: 4, 7, 7, 9, 13) |
|---|---|---|
| Mean | Sum of all values ÷ number of values | |
| Median | Middle value when data is sorted | (3rd value of 5) |
| Mode | Most frequently occurring value | (appears twice) |
| Range | Maximum value − Minimum value |
Data visualizations convert numerical data into graphical form, making patterns and trends easier to identify. The choice of chart depends on the type of data and the message to communicate.
| Data Type | Best Chart |
|---|---|
| Comparing categories | Bar Chart |
| Parts of a whole | Pie Chart |
| Trend over time | Line Graph |
| Relationship between two variables | Scatter Plot |