T1 672007238 BAB III

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Chapter 3

Methodology

3.1 Research Method

The method that is used in this research is Waterfall Method. Waterfall Method is systematic and sequential method. Figure 3.1 is showed the structure of Waterfall Method.

Figure 3.1 the Structure of Waterfall Method (Sommerville, 2004) 3.1.1 Requirement analysis

Cho et al (2002) build a recommender system based on web mining and decision tree induction. If the Cho’s recommender system applies Mobile Phone as the item to be recommended, the taxonomy can be seen at Figure 3.2.This recommender is not consider the weight of every specifications of the mobile phone. Every user has their own consideration, and it is not always depend on what they need but also what they want (Setyawan, 2010). So, that recommender system needs another algorithm that also considers the weight of the specification of mobile phone, and the algorithm is Extended Weighted Tree Similarity. An early research has been held to measure

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what kind of specification of mobile phone that user need. Figure 3.2 is the format of the questionnaires and figure 3,3 shows the result of the early reseach.

Figure 3.2 Questionnaire format of early research

In previous research about Extended Weighted Tree Similarity, Yulianti (2010) had suggestion for next research about the application of that algorithm to make it become online application because online application can update the data automatically if the source is updated. Figure 3.3 shows the example of visualization of XML tree of mobile phone that is used by this algorithm.

Figure 3.3 Result of the questionnaire

So, form the analysis from the previous research about the system and algorithm above, it can be concluded that

Dalam memilih mobile phone yang akan anda beli, factor apa saja yg anda pertimbangkan?

1. Harga 2. Vendor 3. Fitur

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what is needed in this research is online recommender system that applies Extended Weighted Tree Similarity Algorithm.

3.1.2 System Design

This system has simple design to make it user friendly. There are just 3 main steps in this system. The steps can be seen at the use case diagram of this application on Figure 3.4. The previous step is requirement for the next step.

The first step of the application is inputting criteria by the user/ user. These criteria will be built into XML tree by the system. And because the algorithm also considers the weight of the criteria, so the user not just input the criteria but also the weighted of every criterion that they input.

Figure 3.4 Use Case Diagram

The second step is searching the mobile phone from web page, in this case from Tabloid Pulsa site page. The user cannot do the second step before finished the first step because the third step, which will run automatically after the search is done, is need XML tree from user input to compare with XML tree of mobile phones from search result use Extended Weighted Tree Similarity and give recommend based on the count result of the algorithm.

The detail of first step can be seen in Activity Diagram of input criteria on Figure 3.5, and Figure 3.6 show the activity Diagram of the second use case, search mobile phone, and the last and the most complex, Activity

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Diagram of Show Search Result show the detail how the algorithm work behind to process the recommendation for user from comparison between XML tree from user input and from web page.

Figure 3.5 Activity Diagram of Input Criteria

There is a little bit difference in Figure 3.5 and Figure 3.6, in process after the building XML tree.

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XML tree from web page need to save in a collection because there will be more than one XML tree that can be created from web page. One mobile phone will be represented by one XML tree. After finished the search, the system will be query all XML trees on the collection and compare its one by one with XML tree from user input to count the similarity. It can be seen in Figure 3.7 Activity Diagram of Show Search Result.

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Figure 3.7 Activity Diagram of Show Result

All activities in the tree activity diagrams can be summarized into one sequence or collaboration diagram. The sequence diagram can be seen on Figure 3.8 and the collaboration diagram can be seen on Figure 3.9. Like the activity diagrams, most of the

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process work behind by the system and the system just need the user to fill the criteria, including set the number of mobile phone to be compare with their criteria and press search button to initiate the starting of the search. The rest process will run automatically after it.

Figure 3.8 Sequence Diagram

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Although most of process are run by system, but process that has user interaction also important. So, this system need user friendly’s user interface. On Figure 3.10, its can be seen the main form of the application, where all the process is started.

Figure 3.10 Main Form

There are 3 main criterias:

 Harga (Price),

 Vendor

 Fitur (Feature)

In right side of every feature, user can decide

bobot (weighted) of every criterion that they choose. If the user chooses one or more criteria, other form will be shown to help user choose for the sub criteria. The form for price can be seen in Figure 3.11, for vendor in Figure 3.12 and for feature in Figure 3.13. Especially for feature form, this is not a final form, because there are some sub criteria for feature. So, other forms will be shown when user chooses one or more sub criteria on feature form. It is different with 2

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other forms, Price and Vendor, there is no other sub criteria under both of them. User also can decide the weighted of every sub criteria.

Figure 3.11 Price Form

Figure 3.12 Vendor Form

There is a little bit differences between price and vendor form with main form in Figure 3.10 and 3.11. Price and Vendor form is final form, there is no more sub criteria under both of them, and so there are fields in the middle of the form for user to input the detail of the criteria.

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Figure 3.13 Feature Form

There are 9 sub criteria under the feature that is shown in Figure 3.13, they are: Dimensi (Dimention), Sound, Kamera (Camera), Data, Baterai (Battery), General, Layar (Display), Memory, Fitur (Feature). The last sub criterion of feature is feature, this sub criteria accommodate other detail criteria that cannot be accommodated by other sub criteria that is mentioned before. The classification of sub criteria

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under the feature is depended of the feature classification on the Tabloid Pulsa’site.

The next step of waterfall method,

implementation, and testing will be discussed at chapter 4.

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XML tree from web page need to save in a collection because there will be more than one XML tree that can be created from web page. One mobile phone will be represented by one XML tree. After finished the search, the system will be query all XML trees on the collection and compare its one by one with XML tree from user input to count the similarity. It can be seen in Figure 3.7 Activity Diagram of Show Search Result.

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Figure 3.7 Activity Diagram of Show Result All activities in the tree activity diagrams can be summarized into one sequence or collaboration diagram. The sequence diagram can be seen on Figure 3.8 and the collaboration diagram can be seen on Figure 3.9. Like the activity diagrams, most of the

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process work behind by the system and the system just need the user to fill the criteria, including set the number of mobile phone to be compare with their criteria and press search button to initiate the starting of the search. The rest process will run automatically after it.

Figure 3.8 Sequence Diagram

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Although most of process are run by system, but process that has user interaction also important. So, this system need user friendly’s user interface. On Figure 3.10, its can be seen the main form of the application, where all the process is started.

Figure 3.10 Main Form There are 3 main criterias:

 Harga (Price),

 Vendor

 Fitur (Feature)

In right side of every feature, user can decide

bobot (weighted) of every criterion that they choose. If the user chooses one or more criteria, other form will be shown to help user choose for the sub criteria. The form for price can be seen in Figure 3.11, for vendor in Figure 3.12 and for feature in Figure 3.13. Especially for feature form, this is not a final form, because there are some sub criteria for feature. So, other forms will be shown when user chooses one or more sub criteria on feature form. It is different with 2

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other forms, Price and Vendor, there is no other sub criteria under both of them. User also can decide the weighted of every sub criteria.

Figure 3.11 Price Form

Figure 3.12 Vendor Form

There is a little bit differences between price and vendor form with main form in Figure 3.10 and 3.11. Price and Vendor form is final form, there is no more sub criteria under both of them, and so there are fields in the middle of the form for user to input the detail of the criteria.

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Figure 3.13 Feature Form

There are 9 sub criteria under the feature that is shown in Figure 3.13, they are: Dimensi (Dimention), Sound, Kamera (Camera), Data, Baterai (Battery), General, Layar (Display), Memory, Fitur (Feature). The last sub criterion of feature is feature, this sub criteria accommodate other detail criteria that cannot be accommodated by other sub criteria that is mentioned before. The classification of sub criteria

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under the feature is depended of the feature classification on the Tabloid Pulsa’site.

The next step of waterfall method,

implementation, and testing will be discussed at chapter 4.