Data mining practices have become the norm as businesses seek to obtain data that can help them understand the market and improve their services. Most businesses today have some level of digital presence. Therefore, people are continuously looking for data online. You can always read more on this topic, if you would like to dig in deeper!
As data mining becomes more prevalent, its vocabulary is also finding its way into everyday conversations. In most of these conversations, you’re likely to hear the terms web crawling and web scraping. Many users use the two interchangeably, and it would be forgivable if you think they are synonyms.
They are not.
Web crawling and scraping refer to two different data mining processes. Even the end-product data you get at the end of each method and their usage are technically different. Sometimes you might employ both processes depending on the type of data you want.
Due to the similarities between the two, a web crawling vs web scraping comparison would not be enough for you to understand the processes. The differences become more pronounced when you first have a good grasp of each of them individually.
How search engines do web crawling
Search engines offer the best model that you can use to learn about web crawling.
The results you get when you search on Google, Bing, Yahoo, or other search engines are catalogs of information available on websites. To create these catalogs, search engines are continuously sending web crawlers to websites.
Web crawlers go by various names like web spiders, crawler bots, web bots, etc.
They are sent into an initial list of websites and explore all the data on those websites. The web bots then categorize or index this information and put it in a database. Your online search results are sets of information retrieved from the database created in this process.
These first set of websites that the crawlers mine data from are commonly known as starting or seed URLs.
In the seed URL websites, the spiders will identify links and hyperlinks. They follow these to other sites and continue with the same process of obtaining, indexing, and storing information in the database.
They add new data to the original indexes. The bots identify links in the latest websites and follow them to new sites. For search engines, this process is virtually perpetual to keep the search results fresh and updated.
Crawling data for your business
You can replicate this web crawling process to obtain data from various websites for your business.
All you need is a set of crawling tools to identify, obtain, and index sets of data websites for easy retrieval. Most bots, like those used by search engines, collect as much information as possible from the site.
For your business, however, you can have them configured to collect the specific sets of data that you need. You can program the spiders to mine data from a particular website. Or to follow the links to the end.
How is scraping different?
Web scraping is also a data mining process, but it is usually more focused or targeted. Data scrapers get the data you need from a raw set of data and put it in a format that’s easier to process or analyze.
For instance, you can have a scraper programmed to get you the stock prices from a given website. To this extent, the scraping tool will do some level of web crawling on the site as it seeks the targeted data. It doesn’t retrieve any other data from the site.
The scraper will then retrieve and present the data in the format you prefer, such as MS Excel.
Scraping is not limited to websites and other online sources. You can scrape data from an offline database, an excel sheet, or other data storage formats. This is generally known as data scraping.
Web crawling vs web scraping
From the above descriptions, we can make the following web crawling vs web scraping comparison:
- In web crawling, the bots usually collect the data from websites indiscriminately. While scraping tools mine targeted sets of data.
- Web scraping deals with more structured sets of data such as prices, and customer contacts, while crawlers collect as much information as possible thus the data is usually unstructured
- The Web crawlers are continuously following links leading from one website to another while most times scrapers mine data from one or few targeted websites
Web crawling and web as complementary components
Most web data mining tools have both web crawling and web scraping properties. This combination, together with other software components such as parsers, make sure you mine quality data.
Looking at the web crawling process, for example, it results in only the indexing or listing out of information. You can’t download it into your PC, just like you can’t download and store search results.
To download the data, you will need to extract it using a web scraping tool. If you have information that needs conversion or modification, the parser component will process it ready for extraction by the scrapers.
The data is then extracted and can be presented in various formats, depending on how the tool was programmed. The data at this stage is well structured. Further analysis can be conducted on it to provide insight into the market, business competitors, or customers.
In modern business discussions, you will often hear that you need to collect data for you to gain an edge over competitors. Collecting data aimlessly, however, will leave you with information that you can’t use to direct your business.
The first step in collecting useful information is getting a good understanding of the various data mining processes and tools. This includes learning the different sets of data that each process can extract.
Web crawling and scraping are some of the most common yet essential practices in data mining. Learning how to practice them efficiently can provide you with all the data you need to understand your business and how it relates to the business environment.