Data Analysis Flashcards
(14 cards)
What is data ?
Data is information, i.e. facts and figures, that have been collated in a way that allows them to be used to inform decision making.
For data to be used effectively we need to present it in the most suitable way.
The most common forms of presenting data include tables, charts, and graphs.
Examples:
daily sales against targets
daily output and faults
machine hours
sales by region
profit levels
annual growth.
Define a pie chart
A pie chart is a circular chart that is split into sectors to show percentages or the relative value of different categories of data.
Evaluate a pie chart
+ Provides a good visual representation of the relative sizes or shares of a whole part, which makes the different categories of data easier to compare
- Pie charts alone do not give very detailed information
+ They give an overall picture of the information being presented.
+ Can help businesses to make decisions.
- They aren’t very effective for showing increases or decreases of proportions over time as trends are not shown and data cannot be extrapolated (however multiple could help identify a trend)
- They do not show causal relationships such as the impact of advertising spend on sales revenue, meaning that additional information would be needed
- Can be outdated
Define bar chart
Bar charts show categorical data using rectangular bars, with the height of the bar representing the frequency for the category. These bars can be presented vertically or horizontally. One axis will show the categories being compared and the other axis will show the frequency.
Evaluate a bar chart
+Bar charts allow data to be presented in a clear format where key values can be highlighted very quickly. - As it shows frequency not just a % idea, specific figures can be shown
+They are particularly useful to summarise a large amount of data in a visual format.
+ Can show some basic trends
- Bar charts can oversimplify data and further explanations may be needed to give an accurate analysis of the data.
- Data can also be manipulated to show false results and patterns.
- Can be outdated
Define histograms
- Histograms look visually similar to bar charts. The main difference is that histograms show quantitative data and bar charts tend to show categorical data.
-The data in a histogram is continuous so there are no gaps between the bars which represent the different intervals.
-The area of each bar is proportional to the frequency for each interval. Both the x-axis and y-axis have a scale.
-In a bar chart the height of the bar indicates the frequency of the category and only the y-axis has a numerical scale.
Evaluate Histograms
+ It shows the shape of the distribution for a large set of data.
+ Histograms are excellent when displaying data which has chronological categories or numerical groupings.
+ Using histograms to display data also helps depict large differences in shape or symmetry of the data collected.
- They cannot be used for exact values as the data is grouped into intervals.
- The effectiveness of data decreases when the range of data is too wide.
- The data is perhaps less meaningful if the groups are very large.
Define Line graphs
Line graphs compare two variables showing a series of points joined by a continuous line, which shows the relationship between the two variables.. The x-axis represents a continuous variable (e.g. time) and the y-axis represents the second variable (e.g. quantity or value).
- Multiple sets of data can be plotted on a line graph as long as they use the same variables.
- Line graphs are a very useful presentational tool for businesses; a vast range of market, economic and financial data can be presented to a number of stakeholders to show business performance and to analyse market trends.
-Line graphs can also represent data for a number of different categories.
Define maps
Maps can shows data that has geographical context.
Ex. concentrations or amounts
- Can be used to highlight geographic successes or concerns from training as well as where opportunities may be
- Can provide a quick overall picture of a situation
- Can’t provide specific information
- Can’t be used to display any kind of data
- May not be representative of of the whole area just an average
Define index numbers
Index numbers make numerical data easier to understand by comparing it to a base year, which is given the index number of 100. Percentage increases push the index number above 100, and percentage decreases push the figure below 100. An index number of 102 means a 2% rise from the base year, and an index number of 98 means a 2% fall.
- They are a useful method of showing changes over time in data and make comparisons easy by putting often complex data into more simple terms
- Index numbers are useful in business because managers are often concerned with the way in which values such as prices paid for raw materials, numbers of employees and customers, sales, output, productivity and profits etc. may change over time.
- Index numbers are often used for economic analysis. Perhaps the most recognised of this sort of data are measures for inflation such as the Consumer Price Index (CPI) or the Retail Price Index (RPI).
Evaluate index numbers
+ One advantage of using index numbers is to compare changes over time and to make the value of these changes clear.
+ This sort of data is useful to managers as it can potentially indicate how much wages and prices should change by.
+ allows different sets of prices to be compared in the same graph, which would not have been possible with raw data.
+ The combination of using index numbers and a line graph gives a clear presentation of the data and helps to show a visible pattern.
+ they allow data with different starting amounts to be easily compared so that rates of change can easily be seen.
Why can data be important ?
In a world where time is money, faster decisions are often beneficial to businesses. If a business produces data in an easier to see and interpret way, then those making decisions can use it more easily and faster.
3 instances when a business may choose to use a pie chart
- Market Share
- Individual product sales as a share of total sales
- Prefrences of something from market research
6 ways we can present data
*Pie chart
*Bar chart
*Index numbers
*Line graph
*Maps
*Histogram
