Stats #11: Computing simple descriptive statistics (December 27, 2000)

Stats #11: Computing Simple Descriptive Statistics

This class will teach you how to recognize different types of data, how to summarize your data, and how to display your data graphically. Please bring a copy of research paper comparing two groups (e.g., new versus standard therapy) for use in class exercises. This class is useful for anyone who needs to summarize or display numerical data. It is also recommended for anyone who needs to interpret simple descriptive statistics. There are no pre-requisites for this class.

In this class, you will learn how to:

recognize various types of data, identify limitations inherent in certain data types;
compute percentiles; and
construct and interpret a box plot;
characterize central tendency and spread of individual variables.

This class does not qualify for IRB Education Credits (IRBECs).

Contents

Overview of the STATS web pages
Consulting services that I provide
Definition: Qualitative data
Definition: Categorical data
Definition: Continuous data
Definition: Nominal data
Definition: Ordinal data
Definition: Interval data
Definition: Ratio Data
Definition: Stem and leaf diagram
Definition: Percentiles
Definition: Box plot
Definition: Sample mean
Definition: Median
Definition: Mode
Definition: Range
Definition: Standard deviation
Please fill out an evaluation form

Overview of the STATS web pages (January 21, 2000)

What are the STATS web pages?

The STATS pages are a collection of handouts that I use in my job as a statistical consultant. The web provides a nice home for these handouts, because as I update my material, the newest version is immediately available to anyone who is interested.

Where can I find STATS?

If you have a web browser, like Internet Explorer or Netscape Navigator, you can surf on over to my site,

http://www.childrensmercy.org/stats

which is also found at http://internet1/stats, if you are attached to the Children's Mercy Hospital network. There are two obsolete sites: http://www.cmh.edu/stats and http://simon/stats. Do not use either of these sites.

Some of the fun stuff you can find on the STATS web pages.

Ask Professor Mean. For the tough Statistics questions that Dear Abby won't touch.

Planning Your Research Study. Things you need to plan for before you start collecting your data.

Selecting An Appropriate Sample Size. How much data do you really need?

Managing Your Research Data. Everything you want to know before you step to the keyboard.

Steps In a Typical Data Analysis. I have my data on the computer. Now what?

How to Read a Medical Journal Article. Reading a journal is hard work. Here's some help.

Professor Mean's Library. Good books and good web sites about Statistics.

... and even more good stuff!!!

This webpage was written, edited by Linda Foland, and was last modified on 07/08/2008. Category: Website details

For CMH employees only: Statistical Consulting Services.

You can get free statistical consulting if you work for Children's Mercy Hospital. Ashley Sherman provide a wide range of statistical consulting services to help you with your research projects. This help can start as early as the initial planning of your research. I also help with the analysis of your data, using SPSS or other statistical software. We can also provide assistance with the preparation of your presentations and publications.

Here area some examples of the services that we have provided:

setting up your research hypothesis,

selecting and justifying your sample size,

writing the statistical methods section for your grant,

preparing randomization tables for your study,

reviewing your surveys for content and quality,

developing a system for entering your data,

choosing an appropriate statistical model for your data,

establishing validity and/or reliability for your measurement scales,

checking for violations of statistical assumptions in your data,

producing graphs and tables for your research publication, and

providing references for new and unusual statistical methods.

Specific statistical advice has been outlined on a series of web pages which can be found at http://www.childrensmercy.org/stats/. The pages provide advice about planning your research, selecting an appropriate sample size, managing your research data, performing a variety of data analyses, presenting research data, and writing research papers.

This webpage was written on 2003-04-30 and was last modified on 2008-07-08. Category: Professional details

Directions to my new office (April 25, 2008).

I have moved to a new office. It is a modular building just north of Children's Mercy Hospital. It is between 23rd and 22nd street, just off of Kenwood Avenue (Kenwood is a small north/south street just west of Holmes). If you need to get from your office to mine, here are some directions written by my Administrative Assistant, Judy Champion.

Take the elevator of the research tower down to the yellow level. Exit the employee parking garage on 23rd Street, walk to Kenwood and cross 23rd Street. Your destination is Building M 3 which is the building closest to 22nd Street. However, the entrance to our building faces Building M 2. It's best to walk into the parking area that is just north of Building M 1 and follow the sidewalk around the west side of building M 2 in order to get to our building's entrance on its south side. Another route would be to exit the Hospital Hill Center Building on Holmes and then walk ' block north to 23rd Street, cross 23rd Street, walk west to Kenwood then north to building M 3 address 2220 Kenwood.

2008-07-14. Send Category: Professional details

What is qualitative data?

There are two separate definitions of this term. Some people use the term "qualitative data" to represent categorical data.

Other people use the term to represent verbal or narrative pieces of data. These types of data are collected through focus groups, interviews, opened ended questionnaire items, and other less structured situations.

Qualitative research is not the same as anecdotal information. Qualitative research is rigorous research with

explicit sampling strategies, systematic analysis of data, and a commitment to examining counter explanations. Ideally, methods should be transparent, allowing the reader to assess the validity and the extent to which results might be applicable to their own clinical practice. -- BMJ 1998; 316:1230-1232.

Denise Polit gives a delightful example of the difference between qualitative and quantitative data in her book Data Analysis and Statistics for Nursing Research.

Here is her example of qualitative data.

Have you felt sad or depressed at all lately, or have you generally been in good spirits?

(Subject 1) Well, I've been in pretty rough shape lately, to tell you the truth. I mean, I haven't felt suicidal or anything like that, but I just can't seem to shake the blues. I just don't see anything to feel hopeful about in my future. I haven't really had anybody to talk to about my problems since my husband died last year.

(Subject 2) I'm not at all depressed. I feel great! I love my new job. And I've lost 20 pounds and feel much healthier than I have in years. I can't remember any period of my life when I've been happier.

Here is her example of quantitative data.

Quantitative: Thinking about the past week, how depressed would you say you have been on a scale from 0 to 10, where 0 means "not at all" and 10 means "the most possible?"

(Subject 1) 9

(Subject 2) 0