NPR Science podcast on advanced Tornado technology

Podcast URL:

http://www.npr.org/2011/06/17/137199914/advanced-tornado-technology-could-reduce-deaths

NPR (http://www.npr.org) website hosts a wide variety of podcasts on current events, science, arts, health and many other topics of interest which are both informative and educational. I chose this particular posting as it discusses a very relevant topic of interest. Tornados this year alone has killed hundreds of people in US and the science to track and forecast its destruction path is relatively new. However, research in this area, particularly in the invention of early warning systems can save numerous lives and minimize property damages. This podcast introduces a new radar system developed and deployed by CASA (Collaborative Adapting Sensing of the Atmosphere). It discusses how this new system is designed in a simple, intuitive manner and gives a firsthand description of how it worked during the recent Tornado events.

While listening to a podcast, the NPR website also lists the related stories and other recent podcasts in the same section. The audio controls are in a pop-up window which also allows you to add the current podcast into your playlist that you can access as a registered member (registration is free).The content of the stories and the convenience of use makes NPR one of my favorite websites.

Week 4: Cognitive Design Principles for Automated Generation of Visualizations- A summary

This paper defines the cognitive principles associated with creating effective visualizations. It further applies these principles to analyze two problem domains that we encounter in our daily lives, creating route maps to find a destination and crafting assembly instructions to construct an object of daily use. Finally, the paper introduces us to concrete Computer algorithms that were designed on the lines of the cognitive principles and that automates the task of laying out route maps and generating assembly instructions.

Visualization helps us in learning a concept and is sometime more powerful than written words in comprehending ideas. In order to create meaningful visualizations, one needs to be trained in the graphic design tools and also need to have a clear understanding of the domain for which the visualization is designed.  Principle of Congruence requires visualizations to follow the mental picture and the Principle of Apprehension states that it should be easily understood by the readers. In that regard, the author talks about route maps and discusses how they are an important example of visualization that is studied in detail. Well compiled maps conform to the cognitive principles by

-          Representing the routes in sequence of paths and the turning points

-          Simplifying the geographical aspects of the path

Based on the above principles, the authors developed a Computer algorithm called LineDrive that automates the task of creating route maps and are used by popular internet map services like www.mapblast.com. The algorithm is designed based on the design ideas that were refined over a period of time and it applies them to perform the labor intensive task to draw the route map based on destination information.

An instruction to assemble an object is another set of visualization that we encounter in our daily life. We have to understand these instructions and apply them to meet our objectives. It is easy to see the differences between a well written and a poorly compiled instruction. Well designed instructions have the following features in common:

-          Sketches to illustrate the structures and spatial relations between assembled components

-          Multiple sketches breaking up the tasks into a sequence of steps

-          Use of 3D constructs to give a better perspective

-          Additional guidelines and illustrations commonly known as Morphograms

-          Accompanying text notes explaining the diagrams in detail

The authors cite studies which show that good instructions consistently improve productivity for people with average craftsmen skills. The authors then describe an algorithm that can automatically generate assembly instruction when it is provided with the geometric model of the completely assembled object and with the information of its individual components. The algorithm derives on the principles of Robotics to automate a complex and repetitive task.

On a final note, the authors discuss the strength of the algorithms by referring to studies which show that the algorithms produce visualizations that betters hand crafted versions. They also reflect the fact that other types of visualization problems can also be automated with cognitive design principles to create powerful solutions.

Week 4: Weather websites compared

The use of images and graphics in websites generally improves the content and enhances its usability. As a result, graphics contents are extensively used in popular websites and with the advent of better design tools, the look and feel and navigation has scaled new heights. However, there’s still a few instances where as a designer you feel that certain aspects of visualization could be tweaked for better results and in the rare occasions you almost wish that the entire site should be reworked for meaningful presentation of data. For the purpose of our discussion, I planned to review weather websites and compare the use of graphics and other illustrations between two sites that (in my opinion) handles similar data but varies significantly in the ease of use and level of clarity.

The Weather Channel (www.weather.com) is a widely visited website, which provides forecasts, alerts, travel updates and other related information. However, the graphics content of the page might be overwhelming to a new visitor as it is packed with information that’s not quite relevant at first appearance. The main area of the webpage carries a rolling snapshot of the top six video clippings where the topic could be as diverse as “Boy carried by Twister” to “Take our Hurricane Quiz”. In terms of relevance, weather is typically a local topic, followed by an interest for nationwide climate and then there’s room for sensational stories. However, the graphics in this site fails to address the primary goal of displaying the local forecasts in a clear and concise manner. In addition, the snapshot of videos change at a high frequency (about once in five seconds) giving the viewer little time to comprehend the text accompanying the graphics. The maps displayed in the main page and in the maps pane don’t clearly give explanation for the symbols used to represent specific weather conditions. There is a key at the top but it is disproportionately small given the size of the entire map. The forecast could be fetched once you are familiar with the site and it has other useful features but the overall presentation of the graphics leaves a lot to be desired.

In comparison, the USA Today Weather (www.usatoday.com/weather/wfront.htm) organizes similar content in a more professional and succinct manner. The main page has a map section on the left and a local forecast on the right which serves the primary purpose of the website right away. The map on the main page could be viewed in five different contexts (Radar, Satellite, Precipitation, Temperature, Pressure fronts). The forecast section gives detailed report of today and has a concise forecast for the following four days. The weather icons are neatly arranged with expected highs and lows for the day. Weather news appears stacked in the bottom part of the website as you scroll down. The maps tab presents more detailed information and there is a comprehensive explanation of the charts on the bottom of the maps.

In summary, the use of graphics in the USA Today weather website enhances cognition as described by the Dual Coding Theory. Visual graphics is seamlessly synchronized with text information and that helps the users to find what they are looking for and navigate with ease to search for further information. On the contrary, the graphics and videos in the Weather Channel website appears in a disjoint manner and interferes with the primary content that majority of users will be interested in. Both sites are at par in terms of the available features and the accuracy of information but vary significantly in terms of the graphics presentation.

Reading with Hypermedia

Hypertext and hypermedia offers exciting possibilities to enhance the experience of traditional reading. At present, bibliophiles across the world are increasingly using computers to read books and recently Amazon.com announced that the sales of eBooks have surpassed printed books. This presents an opportunity for designers and technologists to introduce features that will enrich reading while retaining the aspects that differentiates it from browsing.

First things first, the Contents should be implemented with hypertexts as it simplifies the task to navigate to a particular section in one stroke. There should also be a link for the reader to move to the Contents from any part of the text. Other sections that are relevant but not directly part of the actual context like Preface, Copyrights and Author’s biography should also be made available through hypertext as it trims the size of the material and in the process makes it more succinct.

A few other features that align naturally and are implemented more efficiently with hypertexts are:

·         Index and Glossary

o    Hypertext based Index and Glossary will make referencing faster across the text

·         Text Search

o    This is not a feature from traditional text but will certainly be very useful for readers to look up particular words across the entire text

·         Errata

o    This section can link to the actual page and summarize the type of error

·         Bibliography, Citations and References

o    This will simplify the reader’s quest for reference and can provide a summary (or complete section where available) on readers’ demand

·         Appendix

o    Most often the material in Appendix is for the readers who would like to explore additional information and hypertext can conveniently relocate this away from the primary topic

Audio/Visual illustrations become extremely important to explain more complex material. Audio tools can provide actual pronunciations for foreign or technical words that are sparsely used. It can also be used in the right context to enhance the reading experience (e.g. the tapes of an historical speech or a first-hand description of a momentous event).

‘A picture is worth a thousand words’. Visual illustrations could be static (e.g. a chart, table, video) or interactive (e.g. a simulation of an actual experiment that takes input from the reader). In both instances, visual aids could be an extremely powerful way to simplify the subject and learn more efficiently.

In summary, hypertext and hypermedia helps to innovate while authoring and to learn faster while reading and offers immense potential for learners in near future.

Week 3: Cognitive load in hypertext reading – Summary

This paper by Diana DeStefano & Jo-Anne LeFevre explores the impact of hypertext reading on learning. The use of hypertext has changed the way a reader constructs information in his mind by navigating through related topics across hyperlinks. The speed of learning is affected by the way the subject is organized, presented and illustrated with the aid of hypertext, graphics and multimedia constructs. The growth of hypertext in general has altered the conventional way of creating educational material by the authors and the eventual learning by the readers. As a result, it’s important to understand the consequences of using hypertext in learning and education. The authors reviewed the results of 38 relevant studies conducted in a period of 14 years (1990-2004) and outlined their findings in this paper.

Cognitive load is defined as the mental effort that a reader employs while reading to gather information and to summarize them into a concrete learning experience. The authors of the paper hypothesizes that the presence of hypertext increases cognitive load on the reader in general and adversely impacts the speed of learning. Some of the studies that strengthen the hypothesis are as follows:

·         Plass, Chun, Mayer and Leutner (2003) found that hypertext with visual annotations impair reading performances substantially. They were examining the impact of both visual and verbal annotations on foreign language texts and found that the visual content often distracted readers as it interrupted their natural pace and increased cognitive load.

·         Zhu (1999), Jacko & Salvendy (1996), Landauer & Nachbar (1985) and Parush, Shwartz, Shtub & Chandra (2005) in independent studies confirmed that the increase in the number of hypertext links increases the difficulty of reading and degrades comprehension performance.

·         McDonald and Stevenson (1996), van Nimwegen, Pouw & van Oostendorp (1999) found that the navigation performance of a reader declines with increasing number of hypertext links. Navigation performance is defined as the speed at which a reader can find answers in a given text after an initial browsing period.

·         Budd, Whitney & Turley (1995) and Lee & Tedder (2003) found that readers with low working memory (WM) spans are more disadvantaged while reading hypertext as compared to people with high WM spans. People with low WM spans have less cognitive capacity in terms of remembering what they immediately read and it’s easier for them to understand structured text with clear topics than hypertexts with minimal contextual information.

·         Lodevijks (1982), Oberauer et all (2000), Witkin, Moore, Goodenough & Cox (1997) and McNamara, Kintsch, Songer & Kintsch (1996) concluded that students with low reasoning ability or less prior knowledge benefits more from logically sequenced texts while students with better skills on the above benefits when they can structure their own reading on hypertext based content.

·         Miall & Dobson (2001) and Barab et al (1999) examined and found that readers could be confused and could miss important material while reading hypertext based literary contents.

There are a few studies which explored similar areas but either didn’t agree with the hypothesis or were inconclusive. Some of them are listed here:

·         Wenger and Payne (1996) didn’t find any notable difference in reading performance for hypertext versus the linear text. Their experiment on the impact of spatial and verbal loads while reading hypertext failed to produce consistent result across different text samples.

·         Lin (2003) and Mohageg (1992) didn’t find any direct degradation in navigation performance with increased number of links. This contradicts with other studies that that concluded the opposite. However, there were no indications that the increase in links improves performance. Also most of the related studies concluded that semantic links hurts performance as it interferes with the hierarchical nature of texts.

·         Baron, Taguesutcliffe, Kinnucan & Carey (1996) and Campbell & Maglio (1999) found that the use of techniques like providing labels or creating descriptors to define a hyperlink actually enhances learning. Both of them improved the accuracy of locating information and raised navigation performance.

In summary, the majority of studies tend to confirm that students with lower reading abilities find it harder to comprehend while reading hypertext based contents while the ones with higher reading abilities adapt better as they can use the flexibility of the hypertext to plan their own learning. This is more or less intuitive as the potential benefits of hypertexts can often be negated by the increased cognitive load in processing the same information through hypertexts, as it tends to increase the difficulty of reading.

Finally, the paper cites a few limitations of the studies and calls for future studies to analyze specific learner characteristics (e.g. prior knowledge, working memory capacity and ability to impose structure) to design their experiments and author their findings.