Web scraping tools divide into two general segments:
- Partial tools
- Complete tools
Partial tools. Partial tools are software for third-party plug-ins. This tool does not provide an API and usually focus on a specific scraping technique, like HTML tables.
A partial tool software may open PDF files, extract eight part or all of its content, and converts pdf to word, excel, and power point.
An example of a partial tool is the Google spreadsheets.
Complete tools. A complete tools are a web scraping services that has the following features for it to be considered as a good alternative:
- A friendly and powerful graphical user interface
- An API which is easy to use and can link and integrate data
- Visual access to websites for data extraction
- Has data caching and storage
- Rational organization and query management for data extraction
A complete tool or a web scraping software provides the following advantages for users:
- Data extraction automation saving time and cost
- Retrieves static and dynamic web pages
- Transforms page contents of various websites
- Formulates vertical aggregation platforms that allows extraction of complicated data from different websites
- Programs that can recognize semantic annotations
- Retrieves all required data
- Accurate and reliable extraction capacity
When you have studied the options and settled on outsourcing your data acquisition needs, you may want to consider the following SLAs before making the finagling the agreement.
- Crawlability. You need to get the assurance of crawlability. And, the expert should be able to go around roadblocks put I place on some websites.
- Scalability. The capability to manage, distribute, monitor, collate, and aggregate the multiple data clusters. Regardless of your current low scale arrangement, anticipating scalability, you will have a well-thought-out solution ready when needed.
- Data structuring capabilities. Every web page has different features, so does the requirement for each project. Therefore, the web scraping service should be detailed in data extraction. You can then validate the data extracted. This attribute is critical when a generic crawler is used in contrast to a written custom rules per site. A note of caution, add quality checks to prevent compromises which happens when surprises crop up.
- Data accuracy. This attribute means having access to uncontaminated and untouched web information. The reason for ensuring accurate data is that any modification done to the data will affect the purpose for which they were extracted. When modifications do occur you may need to have these data cleaned by the expert.
- Data coverage. It is inevitable at times to miss pages during data extraction. This happens when:
– Page does not exist
– Fast loading of data
– Page time out
– Data extraction never reached the page
Such lapses can be avoided by keeping a log, being alert to what data crept in, and arriving at a tolerance level so the expert can configure the program accordingly.
- Adaptability. The dynamic market accounts for changes in the process you choose. Inform the expert of your changes to gain a more competitive edge. Check how your expert adapts to the changes you do.
- Availability. This attribute refers to the availability of the right data at the right time. Inform your expert when you need and expect the data. Most reputable web scraping service companies guarantee 99% deliverables in their delivery channels.
- Maintainability. Like data extraction and structuring of information, monitoring is equally important for regular feeds. Know what is included in the project and other details you may need to know. Web data change in an accelerated fashion. Your expert should be knowledgeable of the changes and quick to do fixing where necessary. By being alert to changes removes the irritants in data management.