Usability review of STEEV interface. Prepared by David Hamill

Transcription

1 Usability review of STEEV interface Prepared by David Hamill 7 October

2 Outline - Summary - Methodology - Findings - Conclusions 2

3 Summary In this report, I (David Hamill) reviewed the interface for the STEEV project (Spatio-Temporal Energy Efficiency Visualisations) for potential usability issues. In the review I found several areas of the interface that could be improved. The most pressing of which concern the way the relationship between preset scenarios and custom ones is displayed as well as the relationship between the scenario controls and the timeline. A full list of observations and recommendations is provided in the Findings section of this report on slide 7. 3

4 Outline - Summary - Methodology - Findings - Conclusions 4

5 Methodology An expert usability review does not involve real users. Instead a usability expert uses the knowledge gained from usability testing and best practices to review a design. The expert explains the nature of each issue, provides a severity rating for it and also a recommendation to resolve it. Because of the nature of a usability review, the report will focus on potential issues found rather than discussing the numerous positive aspects of the interface. 5

6 Use of illustrated examples In places, I may have provided an illustrated example of how a recommendation could be achieved. These should not be taken as a recommendation that the interface should be designed in this exact way. Instead it s an attempt to use fewer words by providing a visual example. Such examples will be basic and lack colour or styling. 6

7 Outline - Summary - Methodology - Findings - Conclusions 7

8 Severity ratings P - Positive finding An example that should be preserved. H - High priority Likely to stop visitors from completing tasks while using the website. M - Medium priority Will cause sufficient friction in completing the task that it either distracts/confuses the user or has an impact on the level of conversions. L - Low priority Likely to cause a problem that will effect the visitor s satisfaction of the site or cause slight friction in completing a task. 8

9 The interface This is the interface at the time the review was carried out. 9

10 Using the forecasting controls H The default setting will confuse some users initially. The interface gives the user the choice between 3 preset scenarios and creating a custom scenario using the sliders. However, because the map defaults to the present day, the sliders are unavailable to them. They can t create a custom scenario unless they select a forecast year from the map interface. It s highly likely that some users will struggle to work this out initially. They may struggle to understand the relationship between the year control and the sliders. Recommendations: Make 2020 the default year so the full controls are released to the user when it loads. 10

11 Using the forecasting controls H The relationship between the preset scenarios and sliders is not made obvious. The interface presents the forecasting scenarios as a choice between 2 options when in fact it s a choice between 4 options. This makes the relationship between the sliders and the preset scenarios rather unclear. The scenarios are separated from the sliders as though they are separate when in fact the 3 scenarios are just pre-settings for the sliders. Recommendations: Combine the Present Scenarios and Variables into a single feature with 4 options ( the 3 scenarios and a custom option.) and a single submit button. If the user moves the controls the currently selected radio button should jump to Custom so it doesn t look as though a preset scenario is being displayed. 11

12 Using the forecasting controls H It s difficult to set a custom scenario when you re in the past view One of the major benefits of the interface is the way it allows the user to play with different scenarios and quickly see the differences. But this means that the user may want to initiate a new scenario from an awkward place. Currently doing so from a past view (say 2000) is difficult. It s possible to choose a preset scenario but not a custom one. Users may have lost sight of the current year they are in and not understand why they can t create a custom scenario. The way it currently works makes sense after you work it out but it s difficult to initially understand why the sliders are deactivated when the map is in the past. Especially when you don t realise it s currently displaying historic data. Recommendations: Instead of deactivating the controls when the user is in the past, allow the user to create a scenario and if they do so jump to 2020 when they submit it. 12

13 Using the forecasting controls H It s easy to misunderstand the data you re looking at The sliders only show the user the currently displayed settings for as long as they are left alone. It s possible to load a custom scenario and then move the sliders and lose track of which scenario you re currently looking at. This is quite likely to happen when the user is attempting to compare a multitude of scenarios. Recommendations: Do not rely purely on the slider position to denote the current settings as the sliders can be moved. Consider options for showing the user what the current scenario they are looking at it. If scales were added (see next slide) then the appropriate position on the scale could be highlighted in some way. However this is just one way it could be done. 13

14 Using the forecasting controls H The sliders don t behave as their visual appearance suggests. Each slider has 5 possible settings that have values attached to them. It s possible to simply click the appropriate place on the slider rather than drag it. Information about each setting is available but in order to get it the user must drag the slider to the option and then leave their cursor over the slider to reveal a tooltip. None of this is implied by the design. Instead it looks totally analogue and there is no indication that further information can be found Recommendations: Provide a scale on the slider to show where the slider can stop. Give each level a tooltip on hover that helps users understand them. The cursor should go to a hand on hover also so that the user understands they can simply click it to get the slider to move to this position. 14

15 Using the forecasting controls M The interface doesn t tell the user that the preset scenario is no longer in use When the user runs a custom scenario, the old preset scenario remains. This can give the impression that the user is still looking at Scenario 2. Recommendations: As explained previously in this report, provide a custom scenario option so the user can see that the preset scenario is not being shown. 15

16 Using the data M Scenarios lack context Over time repeated users will learn what these scenarios are but the new user could be helped by giving the scenario it s descriptive name (such as faint hearted) Recommendations: Add the short name to the scenario options so the user quickly understands them. This will help the user understand what they are looking at when they see the data. 16

17 Using the data H Hiding the legend and output model is not helpful In order to correctly interpret the data, the user will need to know which model is being displayed and also be able to reference the colours against the legend. It would therefore be more helpful if they could see this information by default rather than having to go looking to see if such a feature existed. Recommendations: Combine the output model selection with the legend and show them by default. Allow them (it) to de hidden or minimised by the user. 17

18 Using the data H The conceptual division between future and the past is not strong enough The attempts the interface is making to explain the divide between historic data and forecast data are introducing usability issues to the interface. I feel this could be handled more effectively simply by using better labelling and headings. The scenario options and slider make no reference to forecast data. The user is instead left to work out why functionality disappears in certain circumstances. Also the headings for the timeline sit below the dates themselves. In this position they may never fall into the user s gaze. Recommendations: Use the word forecast within the scenario controls in a way that reinforces the idea that this will only generate data for 2020 onward. Position the headings for the timeline above the year options rather than having them below. This will make it more likely that they are noticed. Consider also saying Historic data and Forecast data to reinforce the idea that the scenarios only apply to forecast data. Consider providing a stronger visual cue for the currently selected year. Also consider making the forecast years stronger visually than historic years. 18

19 Using the data M The Play option may waste the user s time. The Play option is very clunky and is likely to be unhelpful to users. However they may not realise this instantly and waste time trying to use it to extract the data they want. The data loads so slowly that by the time one set has loaded it s difficult to remember how the previous year looked. Even when run a number of times the data doesn t really load a great deal faster. Recommendations: Remove the play option and explore ways of allowing users to compare the data across the timeline. This could be through a print option or exporting image files of the data for each year. It could mean generating a PDF that contained the data for each of the years. There are numerous ways of doing this but this Play option is likely to fall short of being useful. If it were to remain, the button is incorrectly placed. It s contextually relevant to the timeline so should be associated with it visually. 19

20 Using the data M Layer options could be improved The ability to turn off the Steev layer is likely to be helpful for users who need to remove it when it s obscuring detail on the map. However it s equally likely that a user may wish to hide the map layer beneath. Also the user must click a + icon in order to see these options. This icon is pretty vague, it could mean anything. Recommendations: Use the word layers and an indicative icon (see below, you can draw this in 2 minutes in MS Visio) for the layer option. Also allow the user to remove either layer. Layers 20

21 Outline - Summary - Methodology - Findings - Conclusions 21

22 Conclusions With a demonstration of the current interface it s perfectly possible to understand how it works and why it works the way it does. However if the interface is to be used without demonstration or some time after a demonstration, some users are likely to struggle with the interface. This is largely due to the restrictions placed upon the controls in some circumstances and the miscommunication of relationships between some of the interface controls. The comments in this report purely relate to user interaction and understanding. It s difficult to comment on the usefulness of the way the information is provided without having the sufficient domain knowledge. 22

23 Some food for thought Example I have made this rough mock up to show some of the ideas discussed in this report. This mock up shows that the user is given 4 scenario options to choose from. There are markers on the slider scales that allow the user to understand how it works. In this example the user has generated a scenario and later moved all the sliders to the minimum levels. The levels being used on the currently available forecast are shown as bold lines. If the user were to hit the Forecast this scenario button the bold lines would all appear at the minimum levels. The currently selected radio button is made bold to make it clear which option has been selected. This means that when the user chooses a preset scenario and then tweaks the slider they are more likely to notice the scenario option jump to custom. The repeated use of the word forecast could help users understand that this will only change the data on future years. 23