Evidence – IDEA https://www.idea.org/blog Fresh ideas to advance scientific and cultural literacy. Thu, 05 Jun 2025 16:49:21 +0000 en-US hourly 1 https://wordpress.org/?v=4.9.27 Changes over time, in photos and maps https://www.idea.org/blog/2013/08/21/changes-over-time-in-photos-and-maps/ https://www.idea.org/blog/2013/08/21/changes-over-time-in-photos-and-maps/#comments Wed, 21 Aug 2013 13:53:04 +0000 http://www.idea.org/blog/?p=4296 Muir Glacier, AlaskaImages gain new meaning when given the context of location or change. Two sites, from NASA and HistoryPin do this to good effect — such as showing the the dramatic melting of the Muir glacier in Alaska, or how a city evolves.

Launched in autumn 2011 by a British nonprofit, HistoryPin pins historical items on a map. Their service demonstrates the potential for a global, crowdsourced database of historical media.

HistoryPinHistoryPin now boasts 277,348 items. Their aim is to encourage a broad audience to take part in local and global history, help people feel closer to the places they live, to conserve and open up global archives, and to become a large global archive of human history. So far, they’re off to a good start. Many cities have several dozen pins, and a few large cities have hundreds.

The challenge of global coverage

In the United Kingdom, HistoryPin’s home country, they have ~50k pins now. Some of those pins are cross-referenced with Google’s street view. For example, here are Elvis impersonators in Westminster, London, in 2006, superimposed on a current street view scene:

Elvis Lives !!! Westminster, London, UK 2006

Despite the apparently high numbers, HistoryPin’s growth appears to be flatlining. They drew ~20k users in the few few months of 2011, helped by glowing press coverage at launch, but only at 30k more users in the last two years. They have 1,353 institutions registered, but few institutions are doing large-scale uploads. It’s unclear why growth is poor. The site is easy to use, and the usage terms are reasonable. They have a web site, as well as Android and iOS apps. One possible problem is that it’s unclear what the long-term future of HistoryPin is, so it’s not necessarily worth investing a lot of time. Also, they have a closed system, with no way to export content back out.

Growth needs to be exponential if HistoryPin has any hope of carpeting the globe. Relative to the U.K.’s 94k square miles of landmass, HistoryPin has barely 1 item for every two square miles. In London’s 607 square miles, HistoryPin has ~390 pins, again, barely 1 pin for every two square miles. HistoryPin would need at least 100x more pins to have serious global coverage. (For a sense of the scale needed for a global view, as of last year, Google Street View had photographed over 5 million miles of unique streets, covering 39 countries and about 3,000 cities, and they are rapidly expanding that.)

Nevertheless, the concept is compelling. Here’s an image from HistoryPin of a train station in Tuscon, Arizona, USA:

Southern Pacific Train Station 419 W Congress St, Tucson, AZ 85701, USA 1923

And here’s an image of the same building, 9 decades later, from Google Street View. It is now a restaurant:

Google Street View, from site of the Southern Pacific Train Station

Going global — from space

A global view is available from satellites. Here is a comparison of Tucson in summery 1984 (left) vs 2011 (right) from NASA’s State of Flux gallery, which posts weekly comparison images from satellites and land-based cameras.

Tucson, Arizona

Tucson, in the Sonoran Desert in southern Arizona, is one of the oldest continually inhabited areas of North America, with evidence of settlements 3,000 years ago. As with many western cities, Tucson was organized on a grid pattern, which can be seen from space. The side-by-side photos show that the city has grown quickly over the past 30 years. Indeed, population in the greater Tucson area has increased from about 600,000 in 1980 to more than one million in 2011. Expansion has been largely in the eastern region since mountains on the north, west and south restrict development.

State of FluxThe State of Flux site is run by Jet Propulsion Laboratory, and California Institute of Technology. It is a convenient launching pad for educators and the general public interested in change. The time periods range from  centuries to days. Some are related to climate change, urbanization, or the ravage of natural hazards such as fires and floods.

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Evaluating evidence https://www.idea.org/blog/2006/03/01/evaluating-evidence/ https://www.idea.org/blog/2006/03/01/evaluating-evidence/#respond Thu, 02 Mar 2006 04:29:09 +0000 http://www.idea.org/blog/?p=264

Creating an atmosphere of discovery by allowing visitors to evaluate evidence.

Problem

You want to explain a multi-faceted problem and have visitors evaluate the evidence.

Solution

Develop a series of web pages, on which they are directed to note their opinion about each piece of evidence and analyze the problem.

If, for example, your site is exploring unusual cancer rates in a community near a chemical factory, introduce the history of the factory and the local community, the nature of the pollution from the factory, and the limitations of different kinds of evidence. These are the degrees of certainty:

Very certain: There is abundant, compelling evidence, and only one reasonable interpretation.

Probably sure: The evidence is very strong, and you can presume an opinion, but another interpretation might be possible.

It proves nothing: The evidence is consistent with the pollution causing disease, but we are speculating and this permissive evidence cannot prove anything.

Present the visitor with a series of pages, on which they are directed to note their opinion about each piece of evidence, and note how certain they are about their conclusion. For each piece of evidence, explain the basis for the evidence, and provide an unbiased explanation of what the evidence means. Alongside every page, show the following options, under a heading, “What is your analysis?” The visitor can click buttons.

This evidence suggests the pollution caused the diseases: Yes; Not sure; No; Undecided

How conclusive is this evidence? Very certain; Somewhat sure; It proves nothing; Undecided

As the visitor clicks through the pages, a dial on the top of the page dynamically adjusts. The dial, labeled “Your Conclusion” has a range of positions, from “Caused” to “Undecided” to “Didn’t Cause.”

On a “Your Conclusion” page, total the pro and con votes. Some votes are “Very Certain,” some are “Probably Sure” and some are “It Proves Nothing.” Add the votes and calculate the overall determination.

Discussion

Allowing visitors to evaluate the evidence themselves creates an atmosphere of discovery. At the end of the experience, tell visitors what the “experts” have concluded. In any good story, the experts often have widely differing opinions.

A related version of this technique is to present the visitor with a series of hypotheses, and the evidence to evaluate them. For example, what disease does a patient suffer? What caused the Space Shuttle Columbia to explode in 2003? Why did the dinosaurs become extinct? For every hypothesis, present the visitor with evidence to review, and keep track of their replies. After evaluating every hypothesis, the web site tells them which hypothesis the visitor thinks is most probable.

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