CERTL Activities 2006

CERTL Program - Week 5

2006-07-21T08:24:00.000-07:00

Goal: To understand why visualizations are used to display data relationships

Activity 1 - Understanding why visualizations are used to display data relationships
Visualizations are graphs, charts, or visual objects that show a trend. These can be very helpful to people because it is easier to notice a change or resemblance in a picture rather than in a large quantity of numbers. The visualization can also reveal other data trends that one originally did not expect to see and would not have noticed by looking at the raw numbers. This can lead to future discoveries and extra understanding. A visualization is also comprehendable to most people even if they have never seen the data; therefore, visualizations can be used as a universal method of explaning information and data relationships.
For example, rather than looking at all of these numbers (I have created a random data set)...

...you can look at the this graph and see how the data is related.

CERTL Program - Week 4

2006-07-14T08:26:00.000-07:00

Goal: To be able to understand hazard curves.

Activity 1 - Understanding Hazard Curves
A hazard curve is a special type of graph that shows how the rate of survival changes over time as a percentage. To obtain this data, researchers will usually keep track of many people for a set period of time. At various checkpoints it will recorded which of the people are still alive and which people have died. The percentage of people that died is then applied to an exponential formula with e as the base (e is about 2.718281828...). Each solution to the exponential equation is recorded with its checkpoint as a point on a graph (checkpoint number, exponential solution) and the points are connected to form a line. The line can then be used to show how hazardous a situation is at various points of time (some times are less hazardous than others, such as a medicine with a dangerous long-term side effect but no short-term side effects). Some examples of hazard curves can be seen below (please note that the data used to create these hazard curves are made up and not real or related to an actual event).

CERTL Program - Week 3

2006-07-07T08:31:00.000-07:00

Goal: To understand how blood pressure works.

Activity 1 - Understanding How Blood Pressure Works
Blood pressure is how well the heart pumps blood throughout the body. There are two numbers that are used when reading blood pressure: systolic and diastolic blood pressure. The systolic blood pressure is when the heart pushes blood out and into the body; the diastolic pressure is when the heart relaxes and pulls blood into it like a sponge. The blood pressure can be read in mmHg (millimeters of mercury) using a pressure cuff. A normal blood pressure is 120/80 (systolic/diastolic); you can also obtain the pulse meassure by subtracting the diastolic blood pressure from the systolic blood pressure. These numbers depend on many variables including age (systolic increases while diastolic decreases), gender (males are higher than females), medications (effects vary depending on the drug), and much more.
These numbers are determined by how well the heart performs each operation. The effectiveness of each function also relies on the elasticity of the heart and the blood vessels in the body. If the blood vessels are stiffer (as one grows older), then they will be unable to flow blood into the heart as easily. If the heart is stiffer (also as one ages), then it will not stretch as much when it relaxes and will add more pressure when it compresses, pushing the blood at a faster rate than it should. This can be dangerous because the blood vessels are fragile; they can break if too much pressure is applied. Hypertension is the term used to refer to the condition of having a high blood pressure.

CERTL Program - Week 2

2006-06-30T17:13:00.000-07:00

Goal: To be able to read a heat map and understand some of the main parts and functions of the brain.

Activity 1 - Reading a Heat Map
Sometimes, a matrix can have a lot of numbers in it, making it very hard to see the variance between every number in it. In order to see the difference, a heat map can be used. A heat map will use various shades of a color to code for each number in the matrix; therefore, the colors can be compared rather than the raw numbers. Below is an example of a matrix converted to a heat map.

Activity 2 - Understanding Some of the Main Parts and Functions of the Brain
The brain is the organ in our body that allows everything to work; it is the control center of all living organisms. It has evolved a lot over time, and each evolution contains the original brain along with more added to it. The brain began in fish as a tube of nerves that were controlled at one point. Later, some of the nerves became sensitive to light and others became sensitive to various molecules; they connected to a movement control center called the cerebellum. This brain can be found in reptiles, but it is unconscious and has mechanical movements.
The next evolution to the brain was the limbic system, which contained many new parts. The thalamus combined the hearing, smelling, and sight senses together, the amygdala worked with the hippocampus to create a basic memory system, and the hypothalamus provided a wider range of reactions to more events. While this brain found in some mammals is still unconscious, the limbic system did allow the creation of emotions. In more advanced brains, though, the amygdala processes fear and the hypothalamus actually helps the body achieve homeostasis, a condition in which an organism is adjusted to its environment. The next evolution formed the cortex, a thin layer of cells that created connections between various parts of the brain; these connections allowed consciousness.
The final evolution of the brain was the addition of the cerebrum. It contains four lobes that control the main functions of the brain. The parietal lobe allows direction, movement, calculation, and recognition; the occipital lobe allows visual processing; the frontal lobes are responsible for thinking, planning, and understanding; and the temporal lobes understand speech (left hemisphere only), respond to sound, and work with memory. Both halves of the brain are connected by the corpus callosum, which also transfers information between the two halves of the brain.
For this entry, I had to use the book Mapping the Mind by Rita Carter. It explains the evolution, anatomy, structure, and functions of the brain. It also tells about some interesting experiments that have been performed in order to better understand the brain's abilities.

CERTL Program - Week 1

2006-06-23T18:33:00.000-07:00

Goal: To learn the how to use Tableau, learn how to use Crystal Xcelsius, and understand surveys when converted to a Spreadsheet format.

Activity 1 - Using Tableau
Tableau (pronounced Tab-loe) is a very special software that allows you to compare specific fields/columns in a spreadsheet, database, or similar file types. It allows you to take a file, choose several fields/columns you want to analyze or compare, and create a chart or graph that shows the comparison. You can also filter the data to display only a certain range of information (for example, product costs between $50 and $125) and mark different fields/columns so that you can see where each one is on the graph. If you want this software, it can be downloaded at www.tableausoftware.com for several hundred dollars. The website also has a demonstration that you can watch so that you have a better understanding of Tableau.
To begin, you will need to open up a file into Tableau. This can be done by either dragging the file over the Tableau icon and dropping it or by using the first option under the Data menu. Once it is open, a side menu with dimensions and measures will appear. Dimensions are blue and are qualitative (words) that can be used as headings; measures are green and quantitative (numbers) that will aggregate (a mathematical function such as SUM, AVG, MIN, MAX, etc.) in order to show a dimension's specific value in relation to the function. Aggregations can be removed if necessary or you can right click on a measure and select "convert to dimension" if the numbers serve a qualitative purpose. An example of this is when answering the question "How many days a week do you watch television?" You want how many people said each value, not the sum of everyone's answer or the average of everyone's answer. Once your dimensions and measures are set, you can drag them into the rows and columns menu and just as quickly as they are dragged to the entry, they will appear in the graph. Several graphs will occaisionally appear on the screen when there are several possibilities for the graph, or they can be put together into one graph by dragging the dimension or measure onto its existing axis (measures) or label (dimensions) to create subclassifications of the main subject.
Most of Tableau's abilities can only be found by playing around with everything, so have fun and try to do anything that you think will work. I have provided you with the basics and there are training sessions that you can sign up for online with extra techniques. Before you can enroll in the Jedi-Knight class, though, you will be required to take an advanced level class.

Activity 2 - Using Crystal Xcelsius
Crystal Xcelsius is a program that, as implied by the name, uses Microsoft Excel (a spreadsheet program). Unlike the built in chart wizard, Crystal Xcelsius (there is also Xcelsius) turns the spreadsheet data into graphs and allows you to tamper with the data in order to see what happens if certain numbers had different values. In order for Crystal Xcelsius to work, you will need Macromedia Flash (I believe it comes with the Crystal Xcelsius software).
As in Tableau, you must upload a spreadsheet to Crystal Xcelsius before you can begin. Once a spreadsheet is installed, you will have a sidebar with various graphs, value input devices, and other elements that can be used for enhancing the appearance of your presentation. When you find something you want to include, drag the object onto your screen and drop; the object will then appear and can be adjusted to your preferences like a PowerPoint object (drag and drop around the screen to move it and drag the corners to resize it). If the object is a graph, it will be set to a default that you can easily change by right clicking on it; a menu will appear and then select "properties." From here, you will see where it has an area that allows linking to specific cells and a square button next to it. Click on this button and once the spreadsheet appears, highlight the cells that you want the graph to display and click "ok." The value input devices will also be set to a default that can easily be altered by selecting "properties" from the right click menu. When the spreadsheet for a cell link appears, you will only choose one cell that will be affected by the device (make sure that the chosen cell is in your graph!). Once you have designed your Crystal Xcelsius page, you can try it out by selecting "preview" from the tool bar (it is next to the PowerPoint symbol). You may then play with the input devices and watch your graph(s) transform; click the "preview" button again to return to the editting screen when you are done.
Like Tableau once again, I could write pages about all of Crystal Xcelsius' hidden features and abilities, but they can all be found by playing with the software. There is also a built in tutorial that you can watch for a better explanation on how to use Crystal Xcelsius. The one thing that you should know about Crystal Xcelsius, though, is that you can put the file into other various presentations such as PowerPoint. This can be done by going under "file," "export," and then select the presentation format you want.

Activity 3 - Understanding Surveys When Converted to a Spreadsheet Format
After taking a survey, it is usually recorded into a spreadsheet where it can be seen and understood as raw data. The problem is that this will usually be seen as a bunch of numbers for answers. This is because many surveys are performed in a multiple-choice format so that there are not infinite qualitative (word) answers that are challenging to compare (good, fine, excellent, etc.). Instead, quantitative (numbers) values are used so that people can compare how many people rate things (1 is good, 2 is average, etc.) with only a few answers that can easily be compared. To compensate for this, there will usually be a survey key in which each question uses a type of data input with a specific name; this name can be found on another list with the possible choices and what each of them represent. In Tableau, this method is referred to as an alias, and it will translate the numbers into the corresponding words. Otherwise, one will need to have both lists out as a reference to eachother. Occasionally, some questions will have a binary format that be understood through boolean logic; in boolean logic, 1 is a positive value such as true, on, or yes and 0 is a negative value such as false, off, or no. Binary answers can also have a third value if the surveyor decides to code an unanswered question, but that will usually be indicated in the key.