Assessment, Statistics, and Research

An excellent example of presenting two sets of data from multiple sources over time can be found in the presentation of polling data on FiveThirtyEight .* The point of  this post is to identify a useful way to present data from multiple sources over time. The charts are continually updated as data from new polls are received*. The data for each of the two main candidates are plotted and a trend line shows the averages for each candidate. From left to right we see the progress based on the dates of each poll. Notes about the chart and the data 1. Percentages can be averaged and yield a meaningful and easy way to interpret multiple sets of data. 2. The narrowing and widening of the trend lines offers a quick glance at what is happening for each candidate or data source. 3. Averaging polls from multiple sources helps avoid bias due to emphasizing preferred outcomes. 4. Below the chart are tables of data showing important information useful to research methods    4.1 Dates ar...

Tracking polls are useful for evaluating changes in attitudes overtime. A simple yet effective approach is to plot the percentages of people responding in one of two ways each time you collect data. In the example from the Washington Post-ABC News poll, the pollsters collected opinions of the public on the way the president was handling the coronavirus outbreak. By connecting the data points with different colored lines, the change is evident at a quick glance. If you are interested in this particular subject, see the article by Clement and Balz, The Washington Post, July 17, 2020. READ MORE about surveys and charts in Creating Surveys on AMAZON and other stores worldwide. Links to Connections My Page      www.suttong.com    My Books   AMAZON           and             GOOGLE STORE   FOLLOW   FACEBOOK   ...

The US president caused a stir when he responded to a journalist question about police violence claiming that  more white Americans are killed by police than are black Americans ( Montanero , 2020). Is the president right? The correct answer deals with how you view the available data. Yes, if you count the  number of people killed by police. But keep reading. No, if you consider the rate of killing compared to the small percentage of Blacks in the US. So, what are the facts? ( Source = Washington Post  July 14, 2020 ) Number of people killed by police by race category Whites 2,499 Blacks 1,301 Hispanic 907 Other 220 Now consider the population sizes in millions Whites 197 Blacks 42 Hispanic 39 Other 49 Learn more about surveys and statistics  in Creating Surveys on AMAZON As you can see, Blacks are killed at a far higher rate than are whites, but more Whites are killed than Blacks. Unfortunately, discussions of race have become politicized. You can see the bar chart...

DATA SOURCE =  https://ourworldindata.org/grapher/total-daily-covid-deaths The number of people dying from COVID-19 has declined since the second half of April. Because we now have so many data points, I plotted half months rather than 7-day periods as before. Note that March and May have an extra day in the second half compared to April and June. I hope that the recent surge in hospitalizations in some US states do not mean a return to higher death counts. Of course, the symptoms can be severe for some survivors. Nevertheless, the death rate is in decline. We are seeing far more infections compared to European nations, which are now going to work and open for international travel. Resistance to safety recommendations appears high in some crowded areas like beaches in the US. The European data suggest what could happen for the US if people would voluntarily follow the scientific guidance about quality masks, safe distances, and hand washing. Avoiding close contact with infected per...

The Racial Microaggression Scale (RMAS) published in 2012 contains 52 items rated on a 4-point Likert Scale and organized in six categories: Invisibility, Criminality, Low achieving/ Undesirable culture, Sexualization, Foreigner/ Does not belong, Environmental Invalidation. Participants rate the items for experience from "never to often." If an act occurred, then they are asked to rate its level of stress from "not at all" to "high level." Sample Items 1. Because of my race, other people assume that I am a foreigner. 18. I am singled out by police or security people because of my race. 23. Other people act as if all of the people of my race are alike. 49. I feel invisible because of my race. The full scale is available from the PsycTESTS database below. Reliability and Validity These factors were assessed and published in 2012. See the reference below. Alpha for the full 52 items was .949 The items were organ...

The vertical bar chart is a useful method to show comparisons provided the data are accurate. The following chart presents data for three large major race groups in the US. Chart from Statista for August 2020-  See their page for current data, charts, and additional resources. According to the US census, the estimated population of the US in 2019 was 328,239,523. The estimated and rounded percentages of the major groups are:   White 77%   Black/ African American 13%   Hispanic/Latino 18% According to Statista.com , police shootings (to death) of Whites declined between 2017-2019, dropped then increased for Blacks, and for Hispanics. Considering the small percentage of the population for Blacks and Hispanics, they fare worse than do Whites. See the statisca chart. Here's the link to the Statista chart . Ad Learn more about creating surveys, including calculating and reporting statistics in  Creating Surveys on AMAZON    or...

If the posted data are accurate, we have an evident decrease on weekly deaths for the 7-days ending May 22 2020, which is the far right column. That is two weeks of decline and much lower than the April 18 column. The bad news is of course that the US has reached 100,000 deaths. Legend M21 to A25 and M1 represent the Month and Day. The numbers below the dates are for the 7-days including the date. For example, M1 = 11,989 deaths in the 7-days before and including May 1, 2020. The first M dates are for March, then A for the April dates, then back to May again for M1 and so forth. The data are beginning to look like a bell curve, but with many states allowing more freedom of movement, it is too early to tell if there will be a rise in a week or two. The data are from https://ourworldindata.org/grapher/total-daily-covid-deaths I use the download data file and create the chart in Excel. Read more about statistics in these two books. Creating Surveys...