# STRAND: Data Management & Probability

DMP - Collecting and Analyzing Data. What do we mean by collecting data?

What do we mean by analyzing data? Why should you collect and analyze data for your evaluation? DMP - How Do You Find the Probability of the Complement of an Event? DMP - Likert Scale. By Saul McLeod published 2008 Various kinds of rating scales have been developed to measure attitudes directly (i.e. the person knows their attitude is being studied).

The most widely used is the Likert Scale. Likert (1932) developed the principle of measuring attitudes by asking people to respond to a series of statements about a topic, in terms of the extent to which they agree with them, and so tapping into the cognitive and affective components of attitudes. Likert-type or frequency scales use fixed choice response formats and are designed to measure attitudes or opinions (Bowling, 1997; Burns, & Grove, 1997). DMP - Likert Scales and Data Analyses. By I.

Elaine Allen and Christopher A. Seaman Surveys are consistently used to measure quality. For example, surveys might be used to gauge customer perception of product quality or quality performance in service delivery. DMP- Mean, Mode, Median, and Standard Deviation. The is the average and is computed as the sum of all the observed outcomes from the sample divided by the total number of events.

We use x as the symbol for the sample mean. In math terms, where n is the sample size and the x correspond to the observed valued . Suppose you randomly sampled six acres in the Desolation Wilderness for a non-indigenous weed and came up with the following counts of this weed in this region: 34, 43, 81, 106, 106 and 115 We compute the sample mean by adding and dividing by the number of samples, 6. DMP - Methods of Sample Selection.

DMP - Methods of Survey. DMP - Misleading Graphs. DMP - Odds Are, It's Wrong. For better or for worse, science has long been married to mathematics.

Generally it has been for the better. Especially since the days of Galileo and Newton, math has nurtured science. Rigorous mathematical methods have secured science’s fidelity to fact and conferred a timeless reliability to its findings. P VALUE A P value is the probability of an observed (or more extreme) result arising only from chance. S. During the past century, though, a mutant form of math has deflected science’s heart from the modes of calculation that had long served so faithfully. It’s science’s dirtiest secret: The “scientific method” of testing hypotheses by statistical analysis stands on a flimsy foundation.

Replicating a result helps establish its validity more securely, but the common tactic of combining numerous studies into one analysis, while sound in principle, is seldom conducted properly in practice. Statistical insignificance How could so many studies be wrong? DMP - Online Statistics Education. Developed by Rice University (Lead Developer), University of Houston Clear Lake, and Tufts University OnlineStatBook Project Home This work is in the public domain.

Therefore, it can be copied and reproduced without limitation. However, we would appreciate a citation where possible. Please cite as: Online Statistics Education: A Multimedia Course of Study ( Project Leader: David M. DMP - Outliers in a Box-and-Whisker Plot. DMP - Plotting Likert and Other Rating Scales. DMP - Sample Size Calculator. This Sample Size Calculator is presented as a public service of Creative Research Systems survey software.

You can use it to determine how many people you need to interview in order to get results that reflect the target population as precisely as needed. You can also find the level of precision you have in an existing sample. Before using the sample size calculator, there are two terms that you need to know. These are: confidence interval and confidence level. If you are not familiar with these terms, click here. Enter your choices in a calculator below to find the sample size you need or the confidence interval you have. DMP - Statistical Analysis and Research Methodology. Statistical analysis is fundamental to all experiments that use statistics as a research methodology.

Most experiments in social sciences and many important experiments in natural science and engineering need statistical analysis. Statistical analysis is also a very useful tool to get approximate solutions when the actual process is highly complex or unknown in its true form. Example: The study of turbulence relies heavily on statistical analysis derived from experiments. Turbulence is highly complex and almost impossible to study at a purely theoretical level. DMP - Stem and Leaf Displays. Stem and Leaf Displays Author(s) David M.

Lane Prerequisites. DMP - Survey Sampling Methods. Sampling method refers to the way that observations are selected from a population to be in the sample for a sample survey.

Population Parameter vs. DMP - True Random Number Service. DMP - When to Add or Multiply Probabilities? DMP - When to Use Mean, Median, or Mode. Introduction A measure of central tendency is a single value that attempts to describe a set of data by identifying the central position within that set of data. As such, measures of central tendency are sometimes called measures of central location. They are also classed as summary statistics.

The mean (often called the average) is most likely the measure of central tendency that you are most familiar with, but there are others, such as the median and the mode. The mean, median and mode are all valid measures of central tendency, but under different conditions, some measures of central tendency become more appropriate to use than others. Mean (Arithmetic) StudyJams. Virtual Nerd.