Data Analysis Flashcards
What is data
Information like facts and figures that have been collated in a way allowing them to be used to inform decision making
Types of data that a business may use
- daily sales against targets
- daily output and faults
- machine hours
- sales by region
- profit levels
- annual growth
Forms data may come in
Tables, charts and graphs
Where is data published
Newspapers, magazines, journals, company annual reports and company websites, gov website, reports from market research agencies
What are pie charts
A circular chart that is split into sectors to show percentages or the relative value of different categories of data.
Effectiveness of pie charts (point and expansion)
- good visual representation of relative sizes or shares of a whole part (some data easier to compare than if same data was presented in a table)
- show market income and market share (overall picture of info being presented)
- help make business decisions
Limitations of pie charts (point and analysis)
- alone don’t give very detailed info
- can’t show increases or decreases of proportions over time (trends are not shown, data cannot be extrapolated)
- don’t show casual relationships e.g impact of advertising spend on sales rev (additional info needed to support data presented)
What are bar charts?
Data grouped into categories using rectangular bars, with the height of the bar representing the frequency for the category
Benefits of bar charts
- data presented in clear format (key values highlighted quickly)
- useful to summarise large amounts of data in visual format
- used widely throughout the business work to show key financial data
Issues with bar charts
- oversimplify data, further explanations may therefore be needed to give accurate analysis of data
- data can be manipulated to show false results and patters
What are histograms?
They show quantitative data and continuous. The area of each bar is proportional to the frequency for each interval.
advantages of using a histogram to display data
- shows the shape of the distribution for a large set of data.
- good at displaying data which has chronological categories or numerical groupings.
- helps depict large differences in shape or symmetry of the data collected
Weaknesses of histograms
- cannot be used for exact values as the data is grouped into intervals.
- effectiveness decreases when the range of data is too wide
- less meaningful if the groups are very large.
What are line graphs?
used to compare two variables, x-axis represents a continuous variable like time, y-axis represents the second variable quantity/value. The line graph shows the relationship between the two variables.
Usefulness of line graphs
presentational tool for businesses; a range of market, economic and financial data can be presented to a number of stakeholders to show business performance and to analyse market trends.
Maps
A good visual way to view data
Index numbers
used in order to make numerical data easier to understand. Always 100. Purpose is to show percentage changes compared with a BASE number
Base year meaning
Where an index starts
An index number of 102 meaning
2% rise from base year
An index number of 98 meaning
A 2% fall
Why are index numbers useful
- show changes overtime in data such as price levels, consumer income levels or economic output and makes the value clear
- allows data to be standardised over time so it’s easily comparable
- help to understand the significance of a change and are easier to interpret than large numbers
- they are often used for economic analysis (measures of inflation)
- allows different sets of prices to be compared in the same graph, would not have been possible with raw data
- allow data with different starting amounts to be easily compared so that rates of change can easily be seen
Limitations of index numbers
- they focus on the change in data, not on the absolute levels
