5 Replies Latest reply on Apr 15, 2015 2:58 PM by Miranda Li

    Viz Makeover - San Francisco Real Estate

    Miranda Li

      I am developing a series of visualization samples to be packaged with our mobile platform Test Fairy.  This is one of the vizzes I recently revised. I thought I would share with the community the changes I have made and why. Comments and suggestions are welcome.


      Below is the original:



      Here is the new one:



      How do you think?  Can you tell what has been changed? Here is a quick list:


      • Removed the bar chart since it didn't add additional value for the map.  The information you get from the bar chart can be gotten through the tooltips of the map
      • Flipped the orientation of the box and whisker plot---fit better with the map, plus you don't have to tilt your head to read the neighborhood names.
      • Changed the measures on the box and whisker plot:  Changed X-axis measure from price per square foot to last sold price, and added price per square foot as color.
      • Formatted the box and whisker plot:  added row banding on the background, lightened the boxes and whiskers so that the dots can be seen through when highlighting from the maps.
      • Changed the color scheme on the map to match the box and whisker plot color scheme:  previous color scheme is neighborhood. Personally I don't think coloring the neighborhood add values to the understanding of the visual. In fact, it might be distracting at times.  By changing the color scheme, now we can see more information from the same viz.
      • Added more filters options to make the viz more useful and feel like a application.


      Again, comments and suggestions are welcome!!

        • 1. Re: Viz Makeover - San Francisco Real Estate
          Bill Lyons

          I love this kind of discussion. I always get some ideas that are valuable in other applications. Of course, there are always differing opinions and personal taste, but see everyone's reasoning is very helpful.


          One thing that would be helpful to me would be to know the purpose or goal. Who is going to use it and for what purpose?Will it be primarily used by analysts to understand the drivers in the market? Realtors who want to get "comps" for pricing other homes to sell? City planning analysts? Presentation to investors or politicians? The answers to these questions could change my opinion about how to best serve the user. Lacking that, my comments are just based on my personal taste.


          Here are my thoughts:

          • I agree with removing the bar chart. When most of the list cannot fit in the window, the value of a bar chart is greatly diminished.
          • I agree with flipping the box and whisker plot, and the change in metric. Easier to read, larger spread in the distribution, and last sold price for x-axis replaces the bar chart.
          • I personally don't see the benefit of the addition of row banding in this case. No harm, no benefit. Lightening to see through is useful.
          • I agree with the change of color scheme on map, for the same reasons as your's.
          • Adding more filters is good, however, I would change a few things:
            • The filters should also apply to the box & whisker plot. If I want to see 3 bedroom houses, I should be able to see the distribution of neighborhoods and cost, as well as the map.
            • Following the philosophy of Few and Tufte, the data should be in the most prominent position: top. As in a car or airplane, controls should be below or to the side of the display. This is especially true if the purpose is presentation or analysis. The only time I put the controls first is if the user's primary purpose is a lookup tool, where the data is meaningless without the filter. (In my opinion.)
          • I also suggest showing the actual sale amount, rather than the heavily rounded "$1M." Seeing "$0M" in a tooltip is not helpful. Was the property really free? Not likely! If necessary, duplicate the field, and set it to standard currency format for use in the tooltip.
          • I would also add the same values that are in the tooltip for the chart to the tooltip for the map, including sale price and price per square foot. Yes, you can get that by selecting it in the map, and then hovering over it in the chart, but those extra steps should be unnecessary.
          • I don't understand the "Neighborhood:" showing in the tooltip for the map, especially since no value shows for it. Remove that.


          I'll be interested to see other's comments.



          • 2. Re: Viz Makeover - San Francisco Real Estate
            Harley Ellenberger

            I agree with all of Bill's comments.  As he stated, knowing the intended audience would help drive the end product.


            A couple other things I might add....

            • Use a URL action to add a link to the property on the Zillow.com site to allow the user to get more info about a particular address.  I'd add this to the tooltips in the map and box/whisker plot.
            • I almost always use the jitter hack on my box/whisker plots, especially when there are a lot of values.  More on that here - Data + Science
            • This is getting picky, but I see some unnecessary font bolding and multiple fonts being used.  I'd unbold the neighborhood names and the filter labels, and use the same font type across the whole dashboard.
            • 3. Re: Viz Makeover - San Francisco Real Estate
              Miranda Li

              Bill and Harley, these are great discussions. Thanks so much for taking the time to do this.  I agree with most of the suggestions you two brought up.  Here are the changes I made:


              • To make the audience more clear, add better titles and subtitles---I would like this to be a app to help home buyers and their agents to find their desired homes, and compare them with the rest of the listings.
              • Changed the sale price from millions to the actual numbers
              • Fixed all the mess in the tooltips---it's ridiculous how often I forgot to clean the tooptips!  Now I have clean and beautiful tooplips with full address, neighborhood, last sold price and price per square foot.
              • Added links to Redfin when people clicking on the marks----Wow, what a awesome idea Harley!
              • Cleaned up the fronts to limit front types to two.

              Things that didn't change and why:

              • Filters still only apply to the map, because I want to people to be able to compare their desired selection with all the rest of the listings.
              • Filters are still placed at the top for a couple of reasons: First, this will be a lookup tool as Bill mentioned; Second, they don't look very pretty on the side in my defined dimensions(ipad landscape).
              • No added Jitter in this case. First, we try to keep all our product samples hack free. Second, this is a small data sets and there aren't huge amount of data points overlapping. However, I immensely enjoyed reading this jitter hack post--the community and Tableau enthusiasts like you amazes me all the time with their masterful skills and ability to come up with innovative solutions. 


              Anyway, thanks again for the great discussions and input. Here is the new viz:





              • 4. Re: Viz Makeover - San Francisco Real Estate
                Bruce Segal



                I like your make over. For whatever it's worth, I like seeing the neighborhood names and think it adds value to add a color to identify them in your map. I'm not from S.F., so I have no idea where the neighborhoods are on the map.


                Your latest version doesn't make it immediately clear. While the box plot shows that Pacific Heights has the highest prices and Portero Hill the lowest, if I'm new to S.F. I'd like  to know where those neighborhoods are on the map so I can figure out which is closest to my office. Word on the east coast is that finding affordable housing in the Bay Area within a  60 minute commute to S.F. is virtually impossible. So as a potential new comer to the area I'd like to see which neighborhoods are the priciest, the least pricy and somewhere in the middle.


                To that end here's a tweak. I created a  dual axis map. I keep your circle map colored and sized by price and $/sq foot, and add a 2d Filled Map behind it. And I color the filled spots by neighborhood name. This way when I click on your box plot all the circles within a neighborhood fall into the boundaries of the neighborhood. We could add the color key for neighborhood name, but I wanted to keep as close to your latest version as possible.


                See the image below. And I've uploaded a tweaked workbook. (ver. 9.0)


                A few other notes:

                1. To outline the neighborhood boundaries, I had to put zip code on the detail shelf. So in fact the filled map is created by the zip codes. Because a neighborhood is comprised of many zips when I put the neighborhood name on the color shelf, all the zip codes that fall into one neighborhood are colored the same color.

                2. Doing it this way (instead of creating a separate set of polygons for the neighborhoods) reveals a weakness in the approach; some zips fall into more than one neighborhood name. And you can see this b/c some grey areas are darker than they should be b/c they are colored grey for each of the 2 or 3 neighborhood names that map to one zip. If you can make the relationship btwn zips and neighborhood names a 1:1 relationship then you can clean up this issue.

                3. The filled maps map your circles somewhat difficult to see. Perhaps someone else has a better solution for dialing them back a bit. My solution is to pick a grey color scale for they filled map and dial the opacity down to 10%. And then to increase the opacity to 80% or so for the colored circles.

                4. When I've  made other dual axis maps like this, I've been able to set them up so that you can hover over the individual marks, and get the tool tips to show for each one while maintaining the filled in map in the background. In other words I should be able to hover over each circle and see the details in the. For some reason I can't figure out, I can't get this dual axis map to work that way. Perhaps someone else here can help out.



                To that

                • 5. Re: Viz Makeover - San Francisco Real Estate
                  Miranda Li

                  Interesting thoughts Bruce.  Great idea to outline the neighborhood boundaries. But I don't really like the feel of having grey shaded areas on the map. What if just outlines with no shade? Plus as the mobile gallery goes, we are not allowed to use tricks and hacks like this one. However it is definitely an interesting idea for other use cases.


                  In fact, we are still in the process of continue improving this viz. We will post more of our work when we make enough progress.