Exercises in Evaluating Word Density in Slides

Exercises in Evaluating Word Density in Slides

The Cain Project in Engineering and Professional Communication

ENGINEERING SERIES

Instructions

• Read each slide and pay attention to the next yellow “Instructions” slide.

• Answer the questions on the yellow instructions slides. As your instructor directs, discuss your answers with another student.

• Try to develop a sense of standards for – what is easily read, – what supports the main point, and – how density affects readability.

Introduction

• Project assigned to examine a common flue gas desulfurization technique for coal-fired power plants

• Look at regulations that make these techniques necessary; some background on the industry; possible energy conservation techniques; and cost analysis of keeping one such plant supplied

Instructions• What makes this slide easy or hard to read?• When you read the first bullet point, did you at

first think you were reading a sentence? Did you have to re-read bullet one?

• How did having several questions in one bullet point (2nd bullet) affect your reading process?

• What names would you give to the kinds of text density you’ve seen on the previous slide?

SO2 Emissions (1980 - 2003)

• In 2003, SO2 emissions were at 10.6 million tons, about 38% of 1980 levels

• Recent increase due to the increase in electricity production by coal and oil-fired plants

• Lowered natural gas production because of rising prices

Instructions

• Why were some of the columns broken into blue and white while others were yellow?

• Did the text points help you understand the color differences?

• How much of the data contained on the graph supported the text points?

• What was the main point about emissions?• What kinds of density and what points about

density will you remember based on this slide?

So how much are we talking?

• SO2 emissions must be:

– 520 ng SO2/J (1.2 lb SO2/million Btu) heat input and 10 percent of the potential combustion concentration (90% reduction) OR

– 30 percent of the potential combustion concentration (70% reduction) when emissions are less than 260 ng/J (0.6 lb/million Btu)

• Plants can purchase “allowances” that permit them to exceed ordinary limits -- for a hefty fee

Instructions• What was your first interpretation of the title?

How did the colloquial phrase affect you? What did it mean in this context?

• When did you first realize that the two indented bullet points were alternatives? What was the most important clue?

• What did “must be” in the first bullet point seem to mean when you first read it?

• What general point would you make about text density in subordinate bullet points, based on your reactions to this slide?

Clean Coal Technology (CCT) Program

• Cofunded by government and industry• Seeks to demonstrate and deploy

advanced clean coal technologies that meet strict government standards

• “Clean coal” -- end aim is to develop technologies that not only suppress a few emission gasses (such as the SO2 and NOx mentioned previously), but form a process that is entirely emissions free

Instructions

• What makes it harder or easier to read the text on this slide?

• Which of your “rules of the road” for text density does this slide appear to obey?

• Which ones does it defy?

• Is text density more of a problem of number of words or of amount of blank space able to indicate groupings?

Flue Gas Desulfurization

Wet• Calcium-based

sorbent in slurry

• Gas reacts with Ca

• Byproducts are both solids + liquids

Dry or Semidry• Injection of dry solid

(limestone) or slurry

• Gas reacts with Ca

• Byproducts are solids

Instructions

• What overall point is this slide making about flue gas desulfurization?

• What helps or hinders your understanding of the supporting points?

• Is it harder to understand the title if the bullet items aren’t parallel in structure?

FGD comparison

Wet

• High degree of SO2 removal

• High sorbent utilization/contact between solids and liquids

• Excellent particulate removal

Dry / Semidry

• Lower degree of SO2 removal

• Less sites of reaction• Good degree of

particulate removal

Instructions

• Could you make this comparison into a table? If so, what would it look like?

• In what ways does the positioning of the text in each column affect your ability to comprehend the slide?

• What rules would you infer about positioning text and amount of text in comparisons?

Power Generation System

Turbines

Condenser

Boiler

Steam, 24.1 MPa, 540°C

Saturated Condensate, 38°C

27.5% Liquid6.55 kPa

CoolingWater25°C

CoolingWater28°C

500 MWe

Instructions

• Where did your eyes go first when you looked at the diagram?

• Why did they position the Power Generation System diagram here?

• Were you glad to see a diagram after several text slides or did variety in the slides make no difference? Why?

• What point is the power generation system diagram making or supporting here?

Results

• SO2 emissions reduced by 45 tons/y• In fifth year, cost is $5 million per ton SO2

• Switch to fluorescents pays for itself in 7 years (assuming constant energy cost)

• Resistance to switching to fluorescents– “Warmer” color of incandescent bulbs– Time required to replace fixtures

• Other conservation methods should be implemented– Reducing overall energy usage

Instructions

• In what sense did you read “Results”? Results of what?

• Without looking back, how many bullet points were in the list of “results”?

• How many bullet points would usually be the maximum number for easy viewing and comprehension?

Conclusion

• Reducing acid rain requires controlling SO2 emissions• EPA regulations and other initiatives work to minimize

emissions• Implementing wet flue gas desulfurization methods

reduces SO2 emissions• Coal transportation is the major operating expense, as

far as raw materials go• Fluorescent bulbs cheaper and greener in the long run• Multiple methods are needed for reducing SO2 emissions

Instructions

• Why does the designer add the phrase “as far as raw materials go” in the following phrase:– Coal transportation is the major operating expense, as far as raw

materials go

• Are the conclusions memorable? • How many can you name without looking back?• The title says only “Conclusion.” Did you take that to mean the

conclusion of the study or of the plural conclusions in the list?• Do you feel rewarded for reading these slides? Were they

interesting to view? Would you be willing to read the slides again?• What are your “take away” thoughts now about the phrases,

“text density” or “ideas/ink ratio”?

More resources are available for you

• under “Engineering Communication” at Connexions at http://cnx.org

• at the Cain Project site at http://www.owlnet.rice.edu/~cainproj

• in your course Communication Folder in OWLSPACE.

Lead through Excellence in Engineering Communication