Stratified sampling - The sampling methods

3.3 The sampling methods

3.3.3 Stratified sampling

Final probability sampling method is stratified sampling and this also called as cluster sampling.

Selected population is divides into groups according to a common characteristic these groups are called as clusters. A random sample is taken from the one or more selected groups. This sampling method is used when the selected population has less influence over the system.

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For do the research we have selected customers according to the random sampling method because it is impossible to make a data profile to each and every customer in the pizza hut and it will be a waste of money and the time. So by using the random sampling method we have selected 20 customers in different age groups. Our main target is the customers who are around age of 15-21, because they are the people who like to visit fast food restaurants regularly. And also by using random sampling we selected the 5 waiters to do our research and we did a good observation on them and also we did a good observation on customers as well.

Customers – we select 20 customers randomly in order to collect data for our system. 1^st we observe them very carefully, how they behave and how they react in the pizza hut. And then we gave them a questioner. Most of the people rejected to fill the questioners because they are on a hurry to go back to their works. But finally we able to get the data from 20 customers of pizza hut.

Waiters- waiters reject to give the data in formal interviews because they have been instructed to not to give company details to outsiders. So we couldn‟t able to do the formal interviews with them. But we manage to ask some questions and we manage to gather some data from them.

Observation session help us very well to understand how the pizza hut system works.

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2. What type of restaurant do you usually tend to visit?

Fast food

Restaurants Café

Pubs

Casual Dining

3. From Sri Lanka‟s leading restaurants, which do you prefer?

McDonalds Dominos

4. What is the reason for you to select that rest aurant(s)?

Good Food Attractive

Good Convenient

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6. Do you leave a restaurant because of bad service from waiters?

Yes

Sometimes No

7. How often do you go through the menu before ordering?

Always

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10. Which of the following methods do you prefer?

A Menu on the wall Menu book

Touch screen

Menus

11. What is your level of computer knowledge?

Very Basic Intermediate Expert

12. Are you familiar with touch screens?

Yes No

13. Would you enjoy a restaurant which uses touch screens to make orders?

Yes No

14. If “No” state your reasons.

15. In your point of view do you think using touch systems for ordering?

(Problems/Advantages)

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3.5 EVALUATION OF THE QUESTIONNAIRE

This questioner is done in order to get the customers ideas and their likes and dislikes. This was based on pyramid structure where we start in close ended questions and move into open ended questions. Final questions are based on the answers which they given in the start of the questioner. And it helps us to identify the expectation of the customers.

Question 1 – question one is based on to get the idea about the age group. By using this question it is very easy to analyze the age groups and their preferences.

Question 2 and Question 3 – this question is mainly giving an idea about the user preference about the restaurant. To check he is a pizza hut customer or not. By using this question we were able to categorize their need and we were able to prioritize them. If they are a regular pizza hut customer we have given them a high priority to them because they are the people who are going to use the proposed system in future.

Question 4 – This question is giving us the idea of the reason for the customer attraction to the restaurant and these questions help us to categorize the users according to their likeness in the restaurants.

Question 5-6 – using high technology mean restaurant has to spend more money to maintain the equipments in the restaurant. So it will affect to the prizes of the food in the restaurant. So this question identifies that weather the customers willing to pay more money for better service. If the customers will not be like to pay more for better service this system will fail. So it is really important to keep a good eye on answers of this question.

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Question 7- 8-9 – this question is based on to identify the user‟s behavior when they want to order the food. We did a good observation too. Outcome of this question will help us to build and design the system. If the customs pay more attention on new items in the menu, then we have to build our system according to that. Every time user uses the system we have to show them the new items. So this question help the developers to get the user preference and user requirements.

Question 10-11-12 – these question will give us the idea how we should design the system and what user like and their computer knowledge. Do they like to change into new technology and do they still want to use the old method to order the food. If they want to use the old method, developers can develop a system which will more similar to the old method but which will use high technology.

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3.6 RESULTS ANALYSIS

Question 1

This shows that most of the people come to pizza hut is around age of 12-18 and to 19-30. So our main focus should be on those age groups and developers should put more attention on this age groups requirement.

[ 54 ] Question 2

This shows most of the people like to go to fast food restaurants. For reason that they like to get a fast and quick service form the restaurants so can do their work without a delay. So developers should design the system in order to give a good and fast service to the customers. If the system take so much time to response and it is so complicated then the customers will not be come to the restaurant.

[ 55 ] Question 3

This question shows that pizza hut is the leading restaurant in Sri Lanka and the reason that they already use a semi touch screen system to order the food. As a result of that they were able to give a good and quality service to the customers which increase the customer satisfactory level.

[ 56 ] Question 4

In this question we have given choices to the customers of the pizza hut and they have selected the reasons for their visit to the particular restaurant. They have select good food and reasonable price as the top 2 priorities and for the 3^rd option they have selected the good service. This is really an important fact on this proposed system. Main reason to implement this system is to give a good service to the customers. So it is really important to get the user response about the service of the restaurant and what they are looking from the restaurant.

[ 57 ] Question 5

Entire system will depend on this question, because if the restaurant going to implement this proposed system it will cost lots of money. So the prices of the food will definitely get increased with the technology, if the customers willing to pay a reasonable amount for the service then company/restaurant can implement the system. If the customers will reluctant to pay extra amount then the company won‟t be able to maintain the system and it will make a bad name impact on the company. But the response we got form this survey was really good. 75% of the people like to pay extra amount of money to get a good service from the restaurant. So it is a really good pulse point to the developers. By analyzing this question restaurant can make the budget high and can purchase the more equipment to the company.

[ 58 ] Question 6

This question and its answers clearly illustrate that most of the people around 50% is expect a good service from the restaurants and around 90% people will leave the restaurant due to the bad service of the waiters. So it clearly shows that if the restaurant wants to increase the number of customers they should give a good service to the customers. Above question also a good question for the developers who is going to develop proposed system. Because people highly expecting the good and fast service from the waiters. So it is really important for the developers to develop the system simple and with less complication.

[ 59 ] Question 7

This illustrate that most of the people check the menu before they ordering the items. So it is really important for the developers to develop the system to give a good usability for the customers to navigate through the menus. It should be very simple and user should be able to check the food items and their prices without making lots of clicks.

[ 60 ] Question 8

Most of the people like to taste the new items in the restaurant. Most of the people like to have a change. So as developers, they should be considering about good method to show the customers what are the new items available in the restaurant so the customers can identify them easily.

Otherwise customers will not be able to identify the new items in the restaurant.

[ 61 ] Question 9

Most of the people prefer to have a touch screen system. When we talk to them they said that it is easy for them to make the order rather than waiting for a waiter to come and take down the order.

They also mention that it will reduce their waiting time on the restaurant. 75% of the people like to use the touch screen system which is a really good point for the pizza hut when they implement this system.

[ 62 ] Question 10

Even though touch screen system is high technological system people who have an intermediate knowledge can handle the system, so 86% of the customers coming to the pizza hut have that knowledge. So it is not been a big problem of how to operate the system but how ever most of the people said they are really like if the developers use single click method because they don‟t like to use double click..

[ 63 ] Question 11

This question highly relevant to the previous question 20% of the people only familiar with the touch screen technology. But as mention above questions this proposed system is very simple one and it should have video tutorials which user will guide through the system. So the user will not be facing much difficulty because they have been guided throughout the process.

[ 64 ] Question 12

Most of the people do like to use the touch screen system because it saves lots of waiting time in the restaurants. Normally in a busy day if a customer enters to the pizza hut then they should wait around 5-10 min till a waiter comes to him to take the order down. So by using this system customers can reduce that waiting time. So people like to use a touch screen system.

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3.7 TASK ANALYSIS

“Task analysis analyses what a user is required to do in terms of actions and/or cognitive processes to achieve a task”

(http://www.usabilitynet.org/tools/taskanalysis.htm)

It is really important to do a task analysis in order to identify the current system tasks as well as the future system tasks. For the reason that by identifying the tasks of the system, developers can easily understand the main process of the system and they may have the ability to understand main tasks in the current system as well as the future system.

For our project we have decide to use the hierarchy chat task analysis. Where each step will represent a one particular task and it is look like a tree. Each branch will have its own sub branches. If the user wants to perform a certain task they should follow the particular branch in order to fulfil the task.

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3.8 REFERENCE

Anon, 2010, Open and Closed Questions, Changing Minds [Online], available from:

http://changingminds.org/techniques/questioning/open_closed_questions.htm, [Accessed 9^th February 2010].

Anon,nd, Sampling Methods, Sampling Methods[Online], available from:

http://www.statpac.com/surveys/sampling.htm, [Accessed 9^th February 2010].

Anon.nd, STAKEHOLDER ANALYSIS, Guidelines for Concept Note [Online], available from : http://www.cphp.uk.com/downloads/GN%20Stakeholder%20Analysis%20Form.pdf, [Accessed 9^th February 2010].

Boutelle.j, 2004, Understanding Organizational Stakeholders for Design Success,boxesandarrows[Online],available from :

http://www.boxesandarrows.com/view/understanding_organizational_stakeholders_for_design_s uccess.com, [Accessed 9^th February 2010]

Kendall et al,nd, Systems Analysis and Design, Information Gathering: Interactive Methods [Online], available from: wps.prenhall.com/wps/media/objects/1597/1636070/PPT04.ppt , [Accessed 9^th February 2010].

Schmeer.k, 2001, Stakeholder Analysis Guidelines, Kluwer Academin, London.

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SUBMITTED BY:

Thaveesha Gamage (CB)

INTAKE:

HF09B1 SE

MODULE CODE & TITLE:

CE00306-2-HCIU

ASSIGNMENT TITLE:

Individual Assignment

SUBMITTED TO:

Ms. Jina Daluwatta

DATE DUE:

09

^th

February 2010

Asia Pacific Institute of Information Technology

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4.0 USABILITY GOALS AND USABILITY ENGINEERING

Usability is one of the main aspects which need to be considered in the process of Computer application development. Though we only discuss about the usability in this area of HCI, it‟s a subject which has a span throughout a lot of commercial areas since its principals and practices are considered as a help to make the output a success.

According to Sharp, et al(2007) Usability in general, is the process of ensuring a product is easy to learn, effective to use and enjoyable from the user‟s perspective. Furthermore, it says that it involves optimization of the interaction of people with the product to make sure the activities they carry out at their day to day life to be efficient.

Furthermore, they say that

More specifically, usability is broken down into the following goals:

 Effective to use (effectiveness)

 Efficient to use (Efficiency)

 Safe to use (Safety)

 Having good utility (Utility)

 Easy to learn (Learnability)

 Ease to remember how to use (memorability).

Effectiveness is a very general goal and refers to how good a product is at doing what it is supposed to do (Sharp, et al 2007; p21)

Efficiency refers to the way a product supports users in carrying out their tasks. An example of where this kind of efficiency mechanism has been employed efficiently is in online shopping.

Once users have all the necessary personal details in an online form to make a purchase, they can let the web site save all their personal details then if they want to make another purchase at that site, they don‟t have to re-enter all their personal details again. A highly successful mechanism patented by Amazon.com is the one-click option, which requires users only to click a single button when they want to make another purchase (Sharp, et al 2007; p21).

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Safety involves protecting the user from dangerous conditions and undesirable situations. For example, where there are hazardous conditions- like X-ray machines or chemical plants- Operators should be able to interact with and control computer-based systems remotely. To make interactive products safer in this sense involves (i) preventing the user from making serious errors by reducing the risk of wrong keys /buttons being mistakenly activated and (ii) providing users with various means of recovery should make errors. Other safety mechanisms include undo facilities and confirmatory dialog boxes that give users another chance to consider their intentions (Sharp, et al 2007; p21).

Utility refers to the extent which the product provides the right kind of functionality so that users can do what they need or want to do. An example of a product with a high utility is an accounting software package that provides a powerful computational tool that accountants can use to work out tax returns. An example of a product of low utility is a software drawing tool that does not allow users to draw freehand but forces them to use a mouse to create their drawings, using only polygon shapes (Sharp, et al 2007; p22).

Learnability refers to how easy a system is to learn to use. It is well known that people don‟t like spending long time learning how to use a system. They want to get started straight away and become competent at carrying out tasks without too much effort. This is especially so for interactive products intended for everyday use, and those used infrequently. To a certain extent, people are prepared to spend longer learning more complex systems that provide a wider range of functionality, e.g. web authoring tools, word processors. In these situations, CD-ROM and online tutorials can help providing step-by-step material with hands-on exercises. However many people find these difficult to relate to the tasks they want to accomplish. A key concern is determining how much time users are prepared to spend learning a product. It seems a waste of a product provides a range of functionality which the majority of users are unable or not prepared to spend time learning how to use (Sharp, et al 2007; p22, 23).

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Memorability refers to how easy a product is to remember how to use, once learned. This is especially important for interactive products that are used infrequently. If users haven‟t used an operation for a few months or longer, they should be able to remember or at last rapidly be reminded how to use it. Users shouldn‟t have to keep relearning how to carry out tasks.

Unfortunately, this tends to happen when the operations required to be learned are obscure, illogically or poorly sequenced. Users need to be helped to remember how to do tasks. There are many ways of designing the interaction to support this. For example, users can be helped to remember to remember the sequence of operations at different stages of a task through meaningful icons, command names and menu options. Also, structuring options and icons so they are placed in relevant categories of options, e.g. placing all the drawing tools in the same place on the screen, can help the user remember where to look to find a particular tool at a given stage of a task (Sharp, et al 2007; p23).

4.1 IMPORTANCE OF USABILITY

Whether it‟s a website or and normal day to day application, designing it according to the usability methods is a key factor in the process of making the product more user-friendly. It may be possible to build a bug free fully functioning system but incorporating it with user-cantered design principles will result in a better- improved product in several areas.

(Windows User Interface Technical Articles. Usability in Software Design. Microsoft Corporation October 2000)

One of the main attributes that determines the common acceptability of any product is usefulness. In this we measure if the actual goals of the product can be achieved by the actual uses the product is capable of. Usefulness is further broken down into two interrelated parts called utility and usability. Utility refers to the amount of tasks or the task which are able for the

In document HCI Final Document (Page 45-176)