What is Data Analysis?

What is Data Analysis? Collecting data, reviewing the data, and making inferences from the data is data analysis. Analyzing data is important in continuous improvement. Data allows you to make sound decisions about the process, product or service.

This Data Analysis Video teaches you the basic tools for understanding, summarizing, and making future predictions with your collected data. Includes MS Excel templates.

Data Analysis Video

What is Data analysis? It is a scientific approach to improvement. Simple data analysis comes down to two terms. I talk about these two terms on this page.

Data comes from everywhere. There is process data, product data, financial data, mechanical data, electrical data, and service data. Every organization improves with their own set of data. If you can’t measure it, you can’t improve it.

The best thing about data is that most data follows the same patterns. Simple statistics can be used to analyze the data. The term statistics seems to scare people. But really, it is quite simple and data analysis in excel is easy.

Let’s start with the types of data. There are two types of data.

  • Variable
  • Attribute

To answer the question - What is data analysis? You have to understand the difference between these two types of data.


Variable Data

Variable data comes from a measurement. This is an actual number.

Examples of the measurement include test scores, weight, length, width, thickness, sales dollars, profit, cycle time, pH, plating thickness, tensile strength, tension, diameter etc. Cad drawings will have many measurements. Financial data includes purchasing costs, sales volume, profits, sales growth etc.


Attribute Data

Attribute data is go / no go, yes / no or good / bad. Attribute data tracks conformance vs nonconformance. It is used when classifying defects. For example, a manufacture that makes glassware may classify defects as broken glass, thin glass, scratches, misshaped, etc.

The result of a variable data measurement could be an attribute. Lets say your measuring the glass thickness and the glass measures below the specification for thickness. You call this defective glass as thin glass. You reject the glass for thin glass. Thin glass is an attribute.

Suppose you measure 100 glasses for thickness and 10 of them were thin class. Then the attribute data for the 100 glasses are 90 are good and 10 are defective for thin glass. 

This Data Analysis Video teaches you the basic tools for understanding, summarizing, and making future predictions with your collected data. Includes MS Excel templates.

Data Analysis Video

Variable Data Analysis

The first step of data analysis is to collect the data. Below is a table of the length of a 2 foot speaker. I went out and measured 100 units of a total of 1000 speakers. The unit is in inches.

What is data analysis or what can we infer from this data? Well, there are many points in the 21 and 22 inches. That is about it.

To make more sense of the data we need to sort it. The below table sorts the data from low to high.

This Data Analysis Video teaches you the basic tools for understanding, summarizing, and making future predictions with your collected data. Includes MS Excel templates.

Data Analysis Video

The first statistical term that we can easily calculate is the range.

Range: = Maximum – Minimum or 22.6 – 21.2 = 1.4

The next thing we can calculate is the average. The average is the center point of the data. There are three types of averages

  • Mean
  • Mode
  • Median

The most common average used is the mean.

Mean : Sum of all the numbers divided by the number of numbers

2199.55 / 100 = 21.9955

Mode is the number that repeats the most in the data set. 22 repeats 12 times. It is the mode

Median is the number that is in the center of the data set. There is 2 numbers in the center of this data set. Both are 22, the median is 22.


Histogram

What is Data Analysis? We can take the data and make a histogram.

  • A histogram is visual representation of the data.
  • The Y axis is the frequency that the number occurs.
  • The X axis is the measurement cells.

Most of the data is centered about 22.

The mean is 21.9955, The mode is 22 and the median is 22. All average data points are 22.

The data is centered about 22. The further away the measurement is away from 22, the less frequent the data appears.

What is data analysis? Data analysis include creating a picture of the data. This picture is called a frequency diagram or a histogram.

This Data Analysis Video teaches you the basic tools for understanding, summarizing, and making future predictions with your collected data. Includes MS Excel templates.

Data Analysis Video

Normal Distribution

There is a curve driven on the data set. This curve is called a bell shape curve because it looks like a musical bell instrument.

When the data has a bell shape curve we call this normal distribution.

When we have normal distribution we can calculate the standard deviation of the sample. Standard deviation measures the spread of the data about the mean. It tells us the width of the bell shape curve.

You can find more on normal distribution here.


Standard Deviation

The formula for standard deviation is:

Step 1: Take each number and subtract it from the mean. Square the results. Then sum each of those.
(21.2 – 22)2 + (21.8-22)2 + (22-22)2+….

Step 2: (Step 1 total) / (100-1)

Step 3: take the square root of step 2.

For the speaker length, the standard deviation is .314

This is a difficult calculation but Microsoft excel can do it easily.


The two terms - What is data analysis?

What is data analysis? We now have 2 statistics that describes our data set. The first is the mean and the other is standard deviation. The mean tells us the center of our data. The standard deviation tells us the spread of the data.

Mean and standard deviation are the most common terms when it comes to data analysis. Understanding these two terms and normal distribution are basic tools for process improvement. This allows us to apply many other tools to making improvement.

This Data Analysis Video teaches you the basic tools for understanding, summarizing, and making future predictions with your collected data. Includes MS Excel templates.

Data Analysis Video

Comment Box is loading comments...

More Info

  • Data and Information

    Data and Information, are often used interchangeably, they don’t mean the same thing

  • Process Improvement and KPOVs

    Lean Sigma is different to many traditional Process Improvement initiatives in its reliance on data to make decisions

  • Histogram Examples: A Picture of Your Data

    See our histogram examples. We discuss normal distribution and how it applies to quality assurance. Histograms are a key process improvement tool.

  • Histogram in Excel

    Follow these steps to create a Histogram in Excel. This includes turning on data analysis, creating bins, and sorting data.

  • Learn Data Analysis Techniques

    When you understand data analysis techniques, you take a big step towards making product and process improvements.

  • Regression

    See our article on regression, includes details, collecting the data, examples, roadmap and possible problems

  • Data analysis in excel

    Data analysis in excel discusses calculating averages, ranges, and standard deviation in Microsoft Excel.

  • Run Chart

    A Run Chart displays the process performance over time. It is a line graph of data points plotted in chronological order. Learn more!

  • Continuous Data

    Continuous data is part of six sigma tools and statistical process control

  • Data Analysis Video

    Download Today. Don’t take chances without understanding your data. Data drives business decisions. But how does this work? This introduction to Data Analysis Video shows you how to gather, summarize, and present data to management and your team. $59.00. Satisfaction guaranteed.

  • Chi Square

    Learn how to apply Chi Square in practice, when to use it , how to insure results

  • Process Capability Studies

    Process capability studies demonstrate the fit of your data to your specifications. Machine process capability determines current and future defects.

  • Anova

    Anova : One-Way Analysis of Variance (ANOVA) is used to compare the means of two or more sample


> >



Quality Assurance Solutions
Robert Broughton
(805) 419-3344
USA
email

Unique QA Products

All Products

Software, Videos, Manuals, On-Line Certifications

8D Manager

Corrective Action Software

Snap Sampling Plans!

AQL Inspection Software

TrainingKeeper Software

Plan and Track Training

StreamLiner Software

Lean and Continuous Improvement



Statistical Process Control

Training Video

ISO 9001:2015 QA Manual

Editable Template

ISO 9001 Calibration Manual

Editable Template

ISO 9001:2015 QMS Kit

Templates, Guides, QA Manual, Audit Checklists

On-Line Accredited Certifications

Six Sigma, Risk Management, SCRUM

All Products

Software, Videos, Manuals, Training Material


Please Recommend Us!

submit to reddit