1、ETSI ETRu261-3 96 3400855 0141711 _ - tTSI T ETR 261-3 October 1996 Source: ETSI TC-HF Reference: DTR/HF-01028-3 ICs: 33.020 Key words: Keypad, MMI, supplementary service Human Factors (HF); Assessment and definition of a harmonized minimum man-machine interface (MMI) for accessing and controlling p
2、ublic network based supplementary services; Part 3: Experimental comparison of two MMls - Simulated UPT access and prototype ISDN supplementary services ETSI European Telecommunications Standards Institute ETSI Secretariat Postal address: F-O6921 Sophia Antipolis CEDEX - FRANCE Office address: 650 R
3、oute des Lucioles - Sophia Antipolis - Valbonne - FRANCE X.400: c=fr, a=atlas, p=etsi, s=secretarat - Internet: secretariat8etsi.fr Tel.: +33 4 92 94 42 O0 - Fax: +33 4 93 65 47 16 Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the for
4、egoing restriction extend to reproduction in all media. O European Telecommunications Standards Institute 1996. All rights reserved. ETSI ETR*261-3 96 W 3400855 0343732 326 Page 2 ETR 261-3: October 1996 Whilst every care has been taken in the preparation and publication of this document, errors in
5、content, typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to “ETSI Editing and Committee Support Bept.“ at the address shown on the title page. ETSI ETR*ZbL-3 96 3400855 OL4L7L3 262 Page 3 ETR 261-3: October 1996 Contents Foreword . 5 Introduction 5 1
6、 2 3 4 5 6 Scope 7 References 7 Definitions. symbols and abbreviations . 7 3.1 Definitions 7 General Introduction 8 4.1 The Problem 8 4.3 The Target . 8 4.2 The Approach 8 Experiment on UPT . 9 5.1 UPT Services . 9 5.2 The UPT user interface 9 5.3 User-to-system interaction in the UPT services . 9 5
7、.4 Task analysis for the UPT services . IO 5.4.1 Tasks . 10 5.4.2 Subtasks for the UPT services 10 5.5 Scenarios for UPT . 10 5.6 Test design for UPT . 10 5.7 Test bed for UPT . 10 5.8 Data capture for UPT . 11 5.9 Subjects . 11 5.1 O Results . 11 5.10.1 Performance data 11 5.1 0.2 Subjective reacti
8、ons 11 Experiment on ISDN 12 6.1 ISDN Supplementary Services 12 6.2 The ISDN User Interface . 13 6.3 The User-to-system interaction in the ISDN services 13 6.4 Task Analysis for the ISDN Services . 13 6.4.1 Tasks . 13 6.4.2 Subtasks for the ISDN services 13 6.5 Scenarios for ISDN 14 6.6 Test design
9、for ISDN . 14 6.7 Test bed for ISDN 15 6.8 Data capture for ISDN . 15 6.9 Subjects . 15 6.10 Performance data 15 6.1 1 Answers to the questionnaire . 16 6.12 Other subjective results . 17 6.12.1 Call Barring and Call Forwarding . 18 6.1 2.2 3-Party Conference . 19 Proposed solutions 20 6.13.1 User p
10、rocedures 20 6.1 3.2 Service codes 20 6.13.3 User model 20 6.1 3.4 Feedback and prompts . 20 6.1 3.5 Terminology . 21 6.1 3.6 Labels 21 6.13.7 Tones 21 6.1 3 ETSI ETRx261-3 96 3400855 0141714 1T9 W Page 4 ETR 261-3: October 1996 6.1 3.8 Display 21 7 Gonclusions 21 Annex A: User-to-system interaction
11、 in the UPT services . 23 A.1 UPT registration 23 A.l . 1 Procedure 23 A.1.2 Remarks 23 A.2 UPT deregistration 24 A.2.1 Procedure 24 A.2.2 Remarks 24 A.3 UPT outcall . 24 A.3.1 Procedure 24 Annex B: Instructions and scenarios for UPT services 25 B.l UPT registration 25 B.2 UPT deregistration 25 B.3
12、UPT outcall . 25 Annex C: Questionnaire on UPT Services . 26 Annex D: User-to-system interaction in the ISDN services 27 D.l ISDN Call Barring (activation) . 27 D.l.l Procedure 27 D.1.2 Remarks 27 D.2 ISDN Call Forwarding Unconditional (activation) 27 D.2.1 Procedure 27 D.2.2 Remarks 27 D.3 ISDN Thr
13、ee-Party Conference 27 D.3.1 Procedure 27 D.3.2 Remarks 27 Annex E: Instructions and Scenarios for the ISDN Services . 28 E.l ISDN Call Barring . 28 E.l.l ISDN Call Barring - Activation . 28 E.1.2 ISDN Call Barring - Deactivation . 28 E.1.3 ISDN Call Barring - Interrogation . 28 E.2 ISDN Call Forwar
14、ding . 28 E.2.1 E.2.2 ISDN Call Forwarding - Deactivation . 28 ISDN Call Forwarding - Activation . 28 E.3 ISDN Three-Party Conference 28 Annex F: Questionnaire on ISDN Services 29 History . 30 - ETSI ETR*2bL-3 96 H 3400855 OlY17l5 035 Page 5 ETR 261-3: October 1996 Fore wo rd This ETSI Technical Rep
15、ort (ETR) has been produced by the Human Factors (HF) Technical Committee of the European Telecommunications Standards Institute (ETSI). ETRs are informative documents resulting from ETSI studies which are not appropriate for European Telecommunication Standard (ETS) or Interim European Telecommunic
16、ation Standard (I-ETS) status. An ETR may be used to publish material which is either of an informative nature, relating to the use or the application of ETSs or I-ETSs, or which is immature and not yet suitable for formal adoption as an ETC or an I-ETS. I nt rod uct i on The Technical Committee for
17、 Human Factors has prepared this ETSI Technical Report to report publicly its work on the assessment and definition of a harmonized minimum man-machine interface for the access and control of public network based supplementary services. It is intended to complement ETS 300 738 3. This ETR constitute
18、s part 3 of a multi-part ETR (“Assessment and definition of a harmonized minimum man-machine interface (MMI) for accessing and controlling public network based supplementary services“), whose parts have the following titles: Part 1: “General approach and summary of findings“; Part 2: “Literature rev
19、iew - Memory and related issues for dialling supplementary services using number codes“; Part 3: “Experimental comparison of two MMIs - Simulated UPT access and prototype ISDN supplementary services“; Part 4: “Experimental comparison of the effect of categorized and non-categorized formats within us
20、er instructions“; Part 5: “Experimental comparison of the CEPT and GSM codes schemes“; Part 6: “Survey of existing PSTN, ISDN and mobile networks, and a user survey of supplementary service use within Centrex and PBX environments“; Part 7: “Experimental evaluation of draft ETS 300 738“. ETSI ETRu263
21、-3 76 3400855 0342726 T71 Page 6 ETR 261-3: October 1996 Blank page 1 Scope This multi-part ETSI Technical Report (ETR) presents the results of the research work conducted to develop a European Telecommunication Standard (ETS) defining a harmonized minimum man-machine interface (MMI) for the access
22、and control of public network based telecommunications services, and in particular supplementary services. This part 3 of the ETR describes the experimental comparison of two MMls, a phase 1 UPI simulation and an ISDN supplementary service prototype. The experiment compared user performance and pref
23、erences within the basic user procedures provided to access both services. The experiment allowed a tentative comparison between an example of a PBI+ (12 keys, tones and voice announcements) and an example of a PBI+ (12 keys, tones, voice announcements and visual messages) interface. 2 References Fo
24、r the purposes of this ETR, the following references apply: 131 41 91 CEPT T/CAC 02: “Subscriber control procedures for supplementary services in modern telecommunication system“. ETS 300 51 1 : “European digital cellular telecommunications system (Phase 2); Man Machine interface (MMI) of the mobile
25、 station (MS) (GSM 02.30)“. ETC 300 738: “Human Factors (HF); Minimum Man Machine Interface (MMI) to public network based supplementary services“. ETR 261 -2: “Human Factors (HF); Assessment and definition of a harmonized minimum man-machine interface (MMI) for accessing and controlling public netwo
26、rk based supplementary services; Part 2: Literature review - Memory and related issues for dialling supplementary services using number codes I. Fay D (1 993): “Interfaces to automated telephone services: Do users prefer TouchTone or Automatic Speech Recognition?“, 14th International Symposium on Hu
27、man Factors in Telecommunications, Darmstadt, p 339. Israelski E (1 988): “An experimental comparison of user performance with alternative access codes for PBX features.“ 12th Symposium on Human Factors in Telecommunications, The Hague. ITU-T Recommendation E.131: “Subscriber control procedures for
28、supplementary telephone services“. ITU-T Recommendation E.161: “Arrangement of figures, letters and symbols on telephones and other devices that can be used for gaining access to a telephone network“. Jones MLR (1 990): “Making numeric command languages more usable.“ 13th Symposium on Human Factors
29、in Telecommunications, Turin, pp 99-106. ETR 261 -1 : “Human Factors (HF); Assessment and definition of a harmonized minimum man-machine interface (MMI) for accessing and controlling public network based supplementary Services; Part 1 : General approach and summary of find i ng s“ . 3 Definitions, s
30、ymbols and abbreviations 3.1 Definitions For the purposes of this part of the ETR, the definitions, symbols and abbreviations given in part 1 IO of the ETR apply. _ ETSI ETR*2bL-3 96 E 3400855 OL4L7L8 844 Page 8 ETR 261-3: October 1996 4 General Introduction 4.1 The Problem New services are being or
31、 will soon be offered on the existing and new networks. The user interface used to access the old plain telephone service was for many decades the telephone set equipped with a rotary dial or a keypad. Whilst the number and complexity of the new services increases (in fact some services are interact
32、ive and require post-dialling data entry), the user interface available to the general public has not substantially changed. Consequently, the access to the services entails entering information in coded form, which creates problems to the users in terms of time spent, errors made and reduced satisf
33、action. Anyway, beside the traditional Phone Based Interfaces (or PBls), new ones are being developed and start to be offered to the users. In this ETR the attention will be focused on the minimum PBls, which use a numeric keypad as an input device. The output, .e. the feedback indications, can cons
34、ist of telephone tones or a combination of tones, announcements and visual messages as explained in the following: PBI: PBI+: 12-button numeric keypad, tones, announcements and text (on visual display). 12-button numeric keypad and tones. - PBI+: 12-button numeric keypad, tones and announcements. -
35、Beside the user interface, other variables are likely to affect the user performance when accessing the services through the PBls: the presentation of the services to the user, the user procedures, the prompting and feedback messages, the output mode (auditory, visual, both) and so forth. 4.2 The Ap
36、proach To gain a better knowledge on these aspects, identify possible problems and suggest solutions, it was decided to perform an objective experiment. Since it was impractical to take into account all the aforementioned variables, the approach was to rely OR the literature, when available 469, and
37、 to integrate this information with first hand experimental data by comparing two different networks, .e. UPT and ISDN. The first phase of UPT was considered because it was the only one consolidated by ETSI STC NA7 at the time of testing. However, the access codes, lack of available standards, were
38、decided on a national basis. As to ISDN, the Italian Pilot was considered. This is not the standard European ISDN, but was the only ISDN available to the user. Given the status of the implementation of these two networks, it was not possible to create similar testing conditions to ease the compariso
39、n task. For example, code schemes, user interfaces and user procedures are defined already for ISDN and are in a preliminary definition phase for UPT. An attempt was made to provide the user instructions in a similar (.e. minimal) way in both networks, taking into account the principle that PBls sho
40、uld be as far as possible self-explanatory, since they are spread all over the world and users are reluctant to read manuals. 4.3 The Target The experimental results were, where possible, extrapolated to derive general guidelines and achieve better usability through: - improvement of the user interf
41、ace and user-to-service interaction; harmonization of the minimum PBI across the networks and the services. ETSI ETRx2bL-3 96 3400855 OL4L7L 780 Page 9 ETR 261-3: October 1996 Service Registration Deregistration Out Cal I In the following, the description of the test bed, test design, methodology, r
42、esults and conclusions for the two experiments carried out on the UPT and the ISDN services are reported separately. Code 1484 XXXXX YYYYY 1 1484 XXXXX YYYYY O 1484 XXXXX YYYYY 8 5 Experiment on UPT 5.1 UPT Services At the time of writing (mid-1993) the UPT services in Italy are in a preliminary def
43、inition phase and available only on emulators. In the experiment the phase 1 services have been used. The operations that users can perform are: - In-call Registration; - In-call Deregistration; - Single Out-call. The relevant codes have been defined provisionally and unilaterally by the Italian net
44、work operator. They are listed below (table 2): Table 2: UPT codes The messages (prompts, feedback, status information, etc.) for these services are not decided yet. The version used in the experiment has been defined for this particular circumstance as to wording, number of repetitions, interruptab
45、ility, error recovery strategy, etc. 5.2 The UPT user interface In the emulation test bed, the aforementioned UPT services are accessed through a telephone set (PBI+) connected to a Sun Sparcstation computer with speech output emulating the service. The telephone set consists of a 12-pushbutton keyp
46、ad (the O to 9 digits and *, #). 5.3 The user-to-system interaction (user actions and system reactions) for Registration, Deregistration and OutCaIl is described in annex A. User-to-system interaction in the UPT services ETSI ETRa2hL-3 96 3400855 OL4L720 4T2 Page 10 ETR 261-3: October 1996 5.4 Task
47、analysis for the UPT services The following tasks and subtasks have been identified: 5.4.1 Tasks - To register; - To de-register 5.4.2 Subtasks for the UPT services - - - - - To go on-hook. To retrieve the codes of the service; To enter the codes of the service; To perceive the acoustic indications;
48、 To understand the acoustic indications (prompts, feedback); - TO go Off-hook; 5.5 Scenarios for UPT The following three scenarios were made up: - To register for InCalls; - To de-register for InCalls; - To register for OutCalls. Each scenario was presented to the users together with name and descri
49、ption of the service and the relevant instructions (annex 8). 5.6 Test design for UPT To evaluate the user performance and satisfaction when using the UPT services listed above, the following experiment was designed. The test subjects were assigned three tasks covering the available services. The order of presentation of the tasks was balanced across subjects to compensate for the learning effect. One hour was allocated for each subject to read the instructions, carry out the tasks and answer the questionnaire and the intervi
