Thursday, March 28, 2013

Understanding scale with Pan and Zoom

Scale has been identified by the American Association of Science (1993) as a cross cutting concept uniting many science areas.  this appears to be borne out by an investigation of experts, the authors found that experts from a huge variety of subject areas all identified understanding scale as key to their topic (eg architects, biologists, cosmologists, physicists ...).
Meanwhile an investigation was done of the educational film 'Powers of Ten'.

 I posted a Google Earth version a while back.  The film has been used a great deal by science school teachers in the States to teach students about scale and the investigation tested its effectiveness in doing this.  Several important points came out of their work:
  • Students 11-14 years old when asked to think of the largest thing they could imagine came up with ideas like football pitch and street.
  • Students are good at comparing scales (which is bigger?) but poor at imaging absolute scale (wildly out when asked how many miles the United States is across).
  • Their performance at understanding scale improved after watching the film.
My thoughts about this are that one of the unsung benefits of using Google Earth in education is its ability to convey scale easily via the power of zoom.  The Powers of Ten film effectively consists of a slow zoom out from human scale to the size of intergalactic space.  This communicates scale via the use of comparative scale - you can see the 10m square disappearing into the centre the centre of the screen as we zoom past the bigger 100m.  
However using Google Earth zoom to convey scale effectively assumes that we:
  • Anchor Points: Provide 'anchor points' for users so they can compare sizes on screen e.g. A grid or set of squares (as in the Powers of 10 film) or showing the area of ice disappearing in the Antartic?  Then show an outline of the country of Wales (or similar) familiar to your users to give a sense of scale. [More on Wales as a unit area cliche]
  • Zoom Speed: If you zoom out or in too fast user's will have trouble following the scales visible.  In the Power's of 10 film they fly at a gentle 1 change of magnitude per 10 seconds, you can go faster than this without confusing user's but it depends on the complexity of what is in view.

Wednesday, March 6, 2013

Google maps canned Streetview

One neat trick with streetview is that you can find a view you like and record it as a URL. This can then be entered into a point pop up.  See two points on part of the walk I did last weekend as an example, it worked nicely on a smart phone too.

View Walk example in a larger map

Teaching applications:
- Field Trip: Define points to be visited on a field trip or way points (eg at this sign by the road, turn left).  These can be visited virtually pre and/or post field trip AND used during the field trip using a smart phone* (see walk example above for how this could work)
- Before and after:  link to current photos of a landscape that has changed (the 'after') and the streetview that acts as the 'before' shot.  Here's an example: people took pictures during the flooding of New York by hurricane Sandy which are compared to the streetview shots.
- Different Landscapes: mark views of different landscapes such as mountains (example around Snowdon), farmland and woodland.  Discuss with students how these are modified by man.

  1. Open Google Maps (you need to be logged into a Google Account: How to create one) and click 'My Places (top leftish) > create a map (red button).
  2. Create a placemark on this new map by clicking paddle icon (top left) and then clicking on screen somewhere on a UK road you want to capture a streetview view.
  3. Open a new browser tab with google maps in ( 
  4. In this new window, drag and drop orange man by Navigation controls (top left) to the location of your placemark .  You will enter streetview.
  5. Navigate around in streetview until you are happy with the view. Click the chain icon ( top left/centre) to create a URL, click 'short URL'.  Copy the string created.
  6. Now return to your first map and in the pop up window type 'street view at this location' or some more logical text. Click 'rich text editor' and block your typed text. Click on the link icon and paste your URL in. Click ok.
  7. Repeat steps 2 to 6 for as many placemarks as you want.  Add lines or areas too if needs be.
  8. Select privacy settings as needed, public means anyone can search for and find your map.  Unlisted means only those with the link can find it but obviously, its not properly private.
  9. When you're done save your map then click 'Done'.  You will go to the home page of the map you've just created.  Click the link button top left, this now links to your new map rather than the view. 
  10. Share the URL with anyone you want to see the map.

*this assumes a decent 3G signal or preloading of data