Survey of public access information retrieval systems

Report

Survey of public access information retrieval systems

ANNA NEWMAN AND MARK MAGENNIS

A London HCI Centre (LI-IC~ project to produce a user interface development environment for screen-based, nondirect manipulation, public use computer systems is described. A survey of available public access computer systems was undertaken to characterize and critically assess the usability of current designs. That part of the survey relating to four particular information retrieval systems is presented. Some serious weaknesses in the user interfaces to these systems are highlighted along with recommendations for improvements. The paper concludes with a general discussion of the major areas of weakness and how human factors guidelines can be used to

improve usability.

Eeywords: public access computer systems, information retrieval, user interface, human factors

An informal survey of public access transaction and information retrieval systems was undertaken by the London HCI Centre (LHC) during November and December 1989 as part of a research project to construct a user interface development environment. User interfaces for this type of computer system are generally characterized by a simple nondirect manipulation input style and VDU-based textual or graphical output. Users interact through buttons, keyboards or touch screens. The aim of the survey was twofold: First, to discover what user interface components and dialogue interaction styles are presently used by these systems. Secondly, to consider what problems are to be found with the existing systems, how they could be overcome, and which other user interface components, interaction styles and techniques would be useful to have available in interfaces to public access systems.

SYSTEMS SURVEYED There are still very few public access computer information systems in operation in the UK. This paper concerns itself with studying only those which are used by completely untrained members of the public. Two leisure information systems are described: a public library system and a road map/route-finding system of

London HCI Centre, Queen Mary & Westfield College, University of London, London, UK

which two employed touch screens and two used a touch,sensitive keypad input device.

SURVEY APPROACH The approach of the survey consisted of observing each system, finding out what was offered and attempting to carry out some appropriate tasks using it. The functionality, presentation and interaction styles of each system was looked into, and various aspects of these areas considered which affect ease of use, including consistency, clarity, attractiveness and the degree of control and power given to the user. What follows in the next section are descriptions of those systems examined and comments on the authors' impressions of using them.

SURVEY

EMU public information system The EMU (Electronic Marketing Systems) terminal is an interactive through-the-window public access information system for tourists. There are currently over 100 installed at tourist information centres around Britain. The system accesses a database of information on places of interest, events, accommodation and leisure facilities such as restaurants, cinemas and theatres. It is also being used to supply the public with information on local business.

DISPLAYS, OCTOBER 1990 0141-9382/90/040193-08 (~ 1990 Butterworth-Heinemann Ltd 193

The user stands outside the building viewing the information on a VDU through the window and interacts with it via a thin plastic film keypad attached to the inside of the glass on which buttons are printed.

EMU is hierarchically menu-driven, utilizing full screen, mainly textual, menus with between four and nine numbered items in each. Selection is made by entering, via a numeric keypad, the digit corresponding to the required menu item. Three coloured buttons above the keypad are used for navigation and are marked 'Touch for main menu', 'Touch for previous page' and 'Touch for more'. Limited use of graphics is involved where an area of the country can be selected from a map containing numbered regions. The leisure information is retrived from a large database which cannot be changed by the user, but is continually being updated and extended by the system administrators.

Typical tasks which the authors tried to perform with this system involved finding the address of bed and breakfast in Looe, Cornwall; and a cheap restaurant in Deal, Kent. After exploring the system for about an hour, the user interface was found to be weak in many areas; these are listed in the following.

Insufficient feedback mechanisms are employed There is no auditory feedback such as button-clicks or beeps, no visual feedback such as highlighting of selections and, since the keypad has a glass surface (the window), no tactile feedback. This makes it difficult to tell whether or not a user action has been recognized. The response time is unpredictable and varies widely, taking up to 15s for some selections. During this time, there is no indication of being in a searching state so it is often unclear whether information is being retrieved or the system has frozen. Coupled with the lack of auditory, tactile or visual feedback, it is easy to assume that the button has not been properly pressed. To appreciate the problems this causes, one only has to observe people waiting for a lift where the level indicator is broken. Many will assume the mechanism is defective and continue furiously pressing the call button until it arrives. In the case of the EMU system some users will find that the required information sometimes appears after a while then immediately disappears due to their still stabbing at the button from the previous attempt.

Inconsistent functionality of input buttons Although the purposes of the coloured buttons are indicated by the text written on them, their functions actually change for some screens. In these cases the new function is indicated in text on the display screen, for instance: 'press red button for other languages', a message which not only contradicts the function written on the button itself but is also of dubious value to people not understanding the present language! If the

entire screen is not read (this information appears at the bottom), it is natural to assume that touching the red button, which is marked 'Touch for main menu', does what it says. Even when a change in its function is not indicated it is unpredictable, not always returning the same menu.

Illogical menu grouping What seems to be the 'main' menu contains four items, namely:

1. England, Wales & Scotland 2. New Zealand 3. Belgium 4. UK Companies

This is a strange list indeed, particularly the inclusion of 'UK Companies' with no relation to the other items. It is also strange to see New Zealand and Belgium listed, but not the rest of the world since these bear no obvious relationship to England, Wales and Scotland or to each other.

Menu layout and use of colour Menus, which contain up to nine items, use four text colours sequentially in order to visually separate items from one another. Despite, or possible because of this, they appear indistinct, cluttered and difficult to read. The use of colour does not necessarily improve a display.

Deeply nested fixed hierarchical menus To access any information involves following fixed menu paths. For instance, to find out about cheap restaurants in Deal, Kent, starting from the main menu requires choosing first 'England, Wales & Scotland', then 'The South East', then 'Deal' (if it turns out to be a town for which information is available), then 'Restaurants and Bars' followed by the price range. This being a fixed hierarchy there is no way, for example, of going directly to information about a particular town. It is extremely tiresome to go through all these menu screens and, even worse, one may eventually discover that there is nothing about the area of interest anyway.

On the positive side, the keypad is visually good, with its large clearly printed keys. Information may be displayed in any one of six different languages and the database appears to contain a considerable amount of leisure information.

R e c o m m e n d a t i o n s for i m p r o v e m e n t s

• Visual improvements could be made through more meaningful and useful employment of colour in the menus. For instance, to indicate the grouping of items with similar meanings.

194 DISPLAYS, OCTOBER 1990

Report • Menus should be sensibly constructed to show logical

collections. • Various forms of feedback could usefully be

employed to show that the user's actions have been recognized and are being dealt with. A system that does not seem to react to inputs does not inspire confidence.

• Improved navigation methods would provide faster access to the information and more flexibility for the users. For example, the option of specifying queries more directly rather than having to follow pre- defined menu hierarchies.

• Greater consistency in the functions of buttons would reduce the likely number of errors and misunderstandings.

Herffordshixe IAbzazies catalogue & information system Hertfordshire Libraries have a library information system for public use supplied by Automated Library Systems (ALS). It employs a touch screen for both input and output. The screen is divided into two parts (Figure 1). The fight third is a fixed function touch panel offering navigation options and system status information. The rest is taken up by a VDU for query input and library information output. The VDU is green phosphor on black while the fixed touch panel has a black background with yellow and orange text, backlit where appropriate.

Interaction is through a six level menu hierarchy.

W ~ Io I . k ~ L ~ . . . Touch HELP anyWne It Is lit ul) on N B ~ (~)~h~on umo I~

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Start again

Help?

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Figure 1. Diagram of ALS's Hertfordshire library System's main menu and touch control panel

The six menus are:

1. Main menu. Buttons for search by name, title, subject or classification number.

2. The type of material required. Choice of books, music recordings, music scores etc.

3. Inputting the details of the required item. A nonstandard, alphabetically ordered keyboard is displayed for inputting the details of an item.

4. A listing of the close matches to request. The list of items starts with the best match. Selecting an item in the list gives summary details.

5. Summary details. A typical summarized library entry.

6. Full details. More complete details of the same item.

At each level it is possible to go, via a single button press, directly back to any of the higher level menus, with the exception of the one for specifying the type of materials required.

The items on the fixed touch panel were displayed only when relevant to the current screen and had the following functions:

Please wait. Often lit when the system is busy searching, though not always. This appears to be a fault. Start again. Similar in function to a 'reset' button. Goes back to the main menu. Help. Context dependent help which is very good. Previous screen. Goes back to the previously displayed screen (not the same as backtracking through the path taken). Recall notes. Recalls previously saved information. The 'full details' of any entry in the database can be appended to the end of a list which is reproduced on making this choice. Only choosing 'start again' erases this list. Scrolling arrows. The scrolling device offers four directions, up, down, left and fight, two of which, curiously, are never available for use (left and fight). Two scrolling speeds are possible, the faster being chosen by touching closer to the arrow heads. This device was found to be clumsy and difficult to use and in our tests it did not always work properly, often failing to respond. Also, the command 'skip' above and below it were never lit and so we wondered what purpose they served.

Each menu has an explanatory title highlighted at the top, beneath which are directions for the use of that menu. These, like the help, are generally quite good.

The system was used by the authors as any other member of the public would, searching to see if there was a particular book or record in the library, searching to find books by a particular author, and searching for books on a particular subject. The following criticisms of the system were noted.

DISPLAYS, OCTOBER 1990 195

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wh,t l ;acks0a0 l Rata,

Start again by another method

Figure 2. Diagram of ALS's Hertfordshire Library System's touch screen keypad for entering item details

Keyboard problems For those who are familiar with a Qwerty keyboard, the alphabetically-ordered keypad (Figure 2) provided for entering a search request is frustrating to use as it takes so long to find the right letter. The keys are too close together resulting in frequent errors. Other facilities provided are buttons to 'Recall the last thing typed' , 'Backspace' and 'Rubout ' which also suffer from being too close. 'Rubout ' , is ambiguous as it actually means 'rub out the whole lot'. The 'Start again by another method' button is similar to the 'start again' item on the static choice side, but does not remove any saved information from the memory. This difference is not explicit.

Touch screen problems Input via the touch screen works by the 'last hit' method whereby pointing to an item, in the case of the VDU, causes it to highlight, and moving the finger off

the item while still touching the screen unhighlights it and highlights any other item the finger moves onto. On removing the finger from the screen, the currently highlighted item is activated. However, the distance between the display surface and the glass of the touch surface is large enough to make selecting more difficult when it is viewed at an angle. This is compounded by the fact that the display surface is curved while the touch surface is fiat so that the distance between the two increases toward the edge of the screen. Also, the touch detection works up to a centimeter from the screen so it is common to drag a finger over another item on lift-off, activating the wrong one.

Performance The overall speed performance of the system is quite poor. Searching is slow and it keeps hanging up with the message:

access to database currently suspended touch here to return to your previous choice list

There is no apparent reason for this. It also crashed once while in use, and the authors were advised by the librarian to switch it off and on again at the wall socket!

There is also a problem with the data that is presented to the user. An attempt was made to search for books by the author Herman Hesse. At screen level four, a list of authors was presented:

Hesse, H ....

Hesse, Herman...

Hesse, Herman 1867-1962...

These are all the one author, but the information on him is shown so as to make a user think that these are three different authors.

The search mechanism works by alphabetic first word matching, and returns a list which starts with the nearest alphabetic match. In this way it could be seen as a scrollable window into the database with the 'best' match at the top of the window. A search for a book named 'Interfacing Thought' resulted in the display of the part of the list starting with 'Interfacing the BBC Micro' and carrying on through 'Intergallactic Space' etc. This produces a lot of unwanted information without actually stating that the requested item has not been found. Similarly, a search for 'cornflakes' turned up a list starting with 'Cook, Sir Kenneth. . . ' which had absolutely nothing to do with cornflakes.

R e c o m m e n d a t i o n s fo r i m p r o v e m e n t s

• The touch screen problems are due to the particular hardware used and are not a problem generally with these devices. This could be easily remedied to enable greater accuracy.

• The overall reliability of the system should be


Report improved although it is impossible to say whether or not the problems encountered were particular to the example under scrutiny.

• Human factors considerations seem to be restricted to the input side. Users should be explicitly informed whether searches are unsuccessful and output should not include confusing information.

• Access methods could be made more flexible. Experienced library users will require more direct ways of searching the database without necessarily having to go through six levels of menus.

• At a more personal preference level, the authors felt that the scrolling device was clumsy and that a Qwerty keyboard could have been offered as a replacement or alternative to the one provided.

Online public information system at St Paul's Cathedral tourist information centre, London The interactive through-the-window system at St Paul's Cathedral tourist information centre is produced by Online Leisure Information. It is entirely text-based (apart from the screen background and company logo) and largely menu-driven with some query-based keyword searching and simple restart and backtracking facilities. It uses colour to separate the different areas of the screen i.e. menu and the prompts for button presses. The input device consisted, like EMU, of a thin plastic film keypad attached to the inside of the window (Figure 3), output appearing on a VDU behind the glass and above the input device.

Menus of numbered items were displayed on the screen and menu selections are made by entering the number next to the required item via the numeric keypad and (usually) pressing the ' # ' button.

Typical tasks at tempted involved finding out what theatre plays were on in the London area and where one could go horse-riding. The main findings were listed.

Long menus over many pages Large menus with too many items to fit on the screen at once are viewed twelve items at a time by pressing the ' # ' button. The number of items in the list is usually displayed alongside it, but not always. If the required item begins with 'A' this is easily accessed, but if it begins with a letter much further on in the alphabet many screens have to be traversed to get there. Some lists have over four hundred items (such as the sports activities list) which, with the slow screen updating (about two seconds) plus the time taken to press the button, can take two minutes or more to get through. A user would have to be very patient to get any information on, say, yoga and they would be frustrated indeed if they reached the end of the list and found that yoga was not even included.

l a c k of feedback There is no feedback to indicate button presses, causing the 'furious button pressing syndrome' mentioned previously. In this system this is particularly problema- tic since the button presses are queued. Thus if the 'BACK' button is pressed three times you go back three screens. If the ' # ' button is pressed three times because the user is not sure whether they pressed it properly the first time, then the next screen may have two ' # ' events sent to it which it may not understand so producing a disconcerting error message. The end result of all this is to leave the user confused.

Inconsistency of input methods The worst example of inconsistency is the use of the ' # ' button. A screen with three menu items might prompt the user with the command Type 1 to 3 then # . Alternatively it may say Type number then # , or Type number # , or just Type number. Furthermore the words then # sometimes flash and sometimes do not, and sometimes it will go on to the next screen without the hash anyway, subsequently flagging an error.

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Figure 3. Diagram of keypad for Online's leisure information system

Poor navigation methods Despite very fast database accessing, browsing is slow due to the slow screen updating and poor navigational methods, mainly the convoluted menu-based subject hierarchy employed. An example of the problems this creates was in the authors' attempt to find a listing of the theatre plays on in London's West End that evening and enough information about them to help the authors choose which to go to. This was chosen as a typical query which a tourist might want to make of the system. The search involved first going through four menus, the last of which supplied a menu of items in alphabetical order running over many screens. On the fifth of these screens, ' theatre ' was found and the authors were presented with a 'yes/no' question and asked to type the name of an area (they entered 'London') . There then followed four more menus until


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a list of plays came on screen. To find out what each play was about meant choosing it from the list and going past a couple of screens of ticket prices and performance times to get to a review. In order to then see the review of a different play involved 'backing up' three times to the list of plays, then choosing another and going through its ticket prices etc. In the end, the reviews turned out to be rather terse and unimagina- five.

Navigation is largely through this vast hierarchical menu system with the occasional opportunity for keyword searches but no other referential links. No maps are provided and there is no indication of what one could expect to find, so long unfndtful searches occur often.

l~,~ling and useless information displayed There is some spurious information shown. For instance, the top line of the display reads like this:

online 01-22.2,1~10 100c Op

'100c' and 'Op' have no discernible meaning at all. One changes from screen to screen while the other remains the same throughout.

Good points There are some good points to this system. The fast database access means that only once was it necessary to wait for the next screen to be found. During this wait we were informed that searching was going on and an increasing row of dots indicated continued activity. The keyword searching, though under-utilized, is tolerant of mis-spelling.

Good use is made of colour to separate screen areas. The menu items are blue, the input prompting is red and the permanent information is green. This is better for instance than EMU's method of different colours for adjacent items.

R e c o m m e n d a t i o n s fo r i m p r o v e m e n t s

• More direct access methods are requested to aug- ment or replace the deep hierarchies and long menus on which the system is based. This could be provided with more query-based searching or navigation aids such as maps depicting information structure.

• Inconsistencies in the instructions provided need to be addressed, particularly where they result in user e r r o r s .

• Feedback should be used to indicate button presses.

Shel l R o u t e F i n d e r touch s c r e e n road at las

RouteFinder is a touch screen system that is installed in many Shell petrol stations around the country. The

Figure 4. Diagram of a section of map .from Shell's RouteFinder system

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Step 110,

T ~ Mms. When required town is highligMed(sbove) touch the enter key for map.

Figure 5. Diagram of query screen from Shell's RouteFinder system

system displays a map of the British Isles at six levels of detail each of which is divided into discrete screen- sized sections. The initial view is a map of the whole of the British Isles and access to more detailed maps i s made either by touching an area of the map to zoom in on (Figure 4) or by inputting the name of a town (Figure 5). Adjacent areas can be accessed by touching one of the eight direction arrows causing the current section to be replaced by its neighbour in that direction. To zoom out to a wider, less detailed view the user touches the 'Zoom out' button.

The system also offers a tutorial and a help facility. When the user begins, he is asked whether he has used the system before. If the answer is 'no', a tutorial sequence is invoked which constitutes all the help sequences strung together. When the user requests help by touching the 'Help' button, a menu of topics is displayed and used to access particular parts of the tutorial sequence. The part of the tutorial sequence is displayed that is appropriate to the selected help.


Report The town index screen allows the user to input a town name and the nearest matches to the name are displayed in the top right-hand corner of the screen. By using the step-up and step-down buttons, the user can highlight any of the names in the display area. Pressing the 'Enter' button will show the area of the map containing the selected town, at the level displayed when the town index screen was selected.

The type of tasks attempted here were to find a particular town on the map and to find a route (the roads we needed to take) between two towns.

This system was found to be more attractive and less trying on one's patience than the other systems looked at. The user interface is simple and consistent, and also pleasing to look at and use. The user is given useful status information (the level of the map being viewed), and much better use is made of graphics than in the other systems. However, basically all that the system does is display sections of maps, so compared to the other systems its function is very simple and the data is far more homogeneous.

Problem with the system

It is difficult to follow a road through more than one section of the map. This is because rather than scrolling the display between adjacent sections, the current one is immediately replaced so the user loses his orientation on the map.

Good points

The system is very easy to use and provides very fast access to the information. It also looks attractive. Instructions for use and the help are excellent.

Recommendations for improvements • A solution to the one problem found is to use a

scrolling map. This could take one of two forms. Either the whole map could be scrollable in different directions by any amount, or the map could remain in discrete sections, but the display would scroll between them. The first solution, although more flexible, would probably also be more difficult for some people to use as it would involve the user keeping their finger on a 'scroll' button until they wish to stop it. People often take some time to get used to this type of device.

Summary and conclusions In presenting their findings in accordance with the original aims of the survey, the authors have attempted to do two things. First, a description has been given of the features and facilities of a number of widely-used public access information retrieval systems. Secondly, features have been highlighted which present problems

and offer some brief guiding principles for improvements. By taking this approach, the authors have intentionally run the risk of appearing unduly negative. However, some of the systems have been found to contain a number of serious deficiencies and limita- tions. This is not only confined to those included in this survey, but is also true of many other computer-based public access installations which have been examined. It should also be noted that the systems discussed were surveyed during November and December of E)89 and may have changed since.

Those systems containing a large amount of information used quite simple dialogue styles mostly based on hierarchies of menus for narrowing down queries. This tends to lead to laborious searches for the users who may be much better served by query-based mechanisms in which they can specify directly what they want, rather than having to access a menu and find the particular item to chose. Deep menu hierarchies can also be avoided by dialogues where more query information is provided at one time rather than being broken down into sub-queries. There may also be a problem of disorientation in a large system where the user has got 'lost'. In such cases it is useful to have facilities for returning to some 'landmark' from where progress can again be made. Where used, menus should form logical hierarchies according to the users perception of the relationship between subjects. These hierarchies should be flexible so that, for instance, users who want to know what activities are available in a particular place can use a different access path from those who want to know where they can carry out a particular activity. Fixed-path access presumes stan- dard requirements for each user, an assumption that should be avoided. By providing an increased range of facilities, however, there is an inevitable trade-off between power and simplicity.

Feedback should always be provided, both to show tha t the user's actions have been recognized and to indicate what the system is doing. Button presses can be indicated by tactile feedback, in which case the user feels a click; visual feedback, on touch screens for example, where the pressed button can highlight; or auditory feedback, a click or beep. To inform the user of the state of the system messages like 'Searching, please wait' are very useful, particularly when com- bined with some indication of continued activity, such as the row of moving dots used by the Online system. Help facilities can provide useful information about how to use the system, particularly where the help given is context-sensitive.

Consistency is an area where many improvements could be made. Buttons with a stated function should always do the same thing. Changes of function should be clearly indicated either by a visual change of the button itself or by altering the explanation which is next to the button. Contradiction and inconsistency leads to


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errors due to misunderstanding. Related to this is ambiguity. For instance, the function 'Go Back' could be understood to mean 'previous screen' rather than 'back up the hierarchy', and the distinction between 'Index' and 'This Index' is perhaps not clear.

There is currently little use made of colour and almost none of graphics. These techniques require more expensive hardware and more sophisticated software, but can considerably enhance the presentation aspects of the user interface. In particular, icons can be used to indicate functionality and without the problems of language understanding (a picture is worth a thousand words). An arrow, for instance, may be preferable to a button marked 'next screen'. Where colour is used care should be taken to ensure that it benefits rather than detracts from the display. Merely using colour because it's available can result in screens which are not easy to look at. Harmonizing and contrasting colours to produce the desired effect is a skill which many companies would do well to employ a graphic artist to provide. Shape and layout are similarly important. Rather than being employed randomly these techniques should be used to underline the functionality and meaning of the display as well as to enhance attractiveness. Colour and graphics are particularly useful for grouping and separating items on a display.

It may be the case for many current systems that the structure of the underlying information database deter-

mines the structure of the user interface. This is a problem which it may not be possible to get round without reorganizing the database itself. These systems would benefit greatly from a more user-centred or task- oriented approach to design in which the main emph- asis is on usability and functionality from the point of view of the public.

The market for public access information retrieval systems is relatively new, but likely to grow rapidly as the technology becomes cheaper and its possibilities are recognized. Human-Computer Interaction (HCI) has much to offer in improving the quality of computerized public access to information. Although the current generation of systems have a lot of very obvious deficiencies affecting their usability, we should expect to see them benefiting in the future from more human factors guidance.

A c k n o w l e d g e m e n t s

The work described in this paper was supported by the Science and Engineering Research Council, through Research Grant PRJ/MMI/151. The authors would like to give special thanks to Dr. Peter Johnson for his advice and support. Also, they would like to thank Christopher E. Hyde for his comments.


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Survey of public access information retrieval systems