QUOTE: “So there’s three things that you really want to do well if you want to be the world’s best search engine you want to crawl the web comprehensively and deeply you want to index those pages and then you want to rank or serve those pages and return the most relevant ones first….. we basically take PageRank as the primary determinant and the more PageRank you have that is the more people who link to you and the more reputable those people are the more likely it is we’re going to discover your page…. we use page rank as well as over 200 other factors in our rankings to try to say okay maybe this document is really authoritative it has a lot of reputation because it has a lot of PageRank … and that’s kind of the secret sauce trying to figure out a way to combine those 200 different ranking signals in order to find the most relevant document.” Matt Cutts, Google
Onsite, consider linking to your other pages by linking to pages within main content text. I usually only do this when it is relevant – often, I’ll link to relevant pages when the keyword is in the title elements of both pages. I don’t go in for auto-generating links at all. Google has penalised sites for using particular auto link plugins, for instance, so I avoid them.
QUOTE: “For the mostpart it should be fine I think the the tricky part that you need to be careful about is more around doorway pages in the sense that if all of these pages end up with the same business then that can look a lot like a doorway page but like just focusing on the content duplication part that’s something that for the most part is fine what will happen there is will index all of these pages separately because from  from a kind of holistic point of view these pages are unique they have unique content on them they might have like chunks of text on them which are duplicated but on their own these pages are unique so we’ll index them separately and in the search results when someone is searching for something generic and we don’t know which of these pages are the best ones we’ll pick one of these pages and show that to the user and filter out the other variations of that that page so for example if someone in Ireland is just looking for dental bridges and you have a bunch of different pages for different kind of clinics that offer the service and probably will pick one of those pages and show those in the search results and filter out the other ones.
You’ll likely compile a lot of keywords. How do you know which to tackle first? It could be a good idea to prioritize high-volume keywords that your competitors are not currently ranking for. On the flip side, you could also see which keywords from your list your competitors are already ranking for and prioritize those. The former is great when you want to take advantage of your competitors’ missed opportunities, while the latter is an aggressive strategy that sets you up to compete for keywords your competitors are already performing well for.
In short, nobody is going to advise you to create a poor UX, on purpose, in light of Google’s algorithms and human quality raters who are showing an obvious interest in this stuff. Google is rating mobile sites on what it classes is frustrating UX – although on certain levels what Google classes as ‘UX’ might be quite far apart from what a UX professional is familiar with in the same ways as Google’s mobile rating tools differ from, for instance,  W3c Mobile testing tools.
QUOTE: “To summarize, a lack of helpful SC may be a reason for a Low quality rating, depending on the purpose of the page and the type of website. We have different standards for small websites which exist to serve their communities versus large websites with a large volume of webpages and content. For some types of “webpages,” such as PDFs and JPEG files, we expect no SC at all.” Google Search Quality Evaluator Guidelines 2017
By 2004, search engines had incorporated a wide range of undisclosed factors in their ranking algorithms to reduce the impact of link manipulation. In June 2007, The New York Times' Saul Hansell stated Google ranks sites using more than 200 different signals.[26] The leading search engines, Google, Bing, and Yahoo, do not disclose the algorithms they use to rank pages. Some SEO practitioners have studied different approaches to search engine optimization, and have shared their personal opinions.[27] Patents related to search engines can provide information to better understand search engines.[28] In 2005, Google began personalizing search results for each user. Depending on their history of previous searches, Google crafted results for logged in users.[29]

While Google is on record as stating these quality raters do not directly influence where you rank (without more senior analysts making a call on the quality of your website, I presume?) – there are some things in this document, mostly of a user experience nature (UX) that all search engine optimisers and Webmasters of any kind should note going forward.

Companies that employ overly aggressive techniques can get their client websites banned from the search results. In 2005, the Wall Street Journal reported on a company, Traffic Power, which allegedly used high-risk techniques and failed to disclose those risks to its clients.[15] Wired magazine reported that the same company sued blogger and SEO Aaron Wall for writing about the ban.[16] Google's Matt Cutts later confirmed that Google did in fact ban Traffic Power and some of its clients.[17]
QUOTE:  Each piece of duplication in your on-page SEO strategy is ***at best*** wasted opportunity. Worse yet, if you are aggressive with aligning your on page heading, your page title, and your internal + external link anchor text the page becomes more likely to get filtered out of the search results (which is quite common in some aggressive spaces). Aaron Wall, 2009
Forget whether or not to put your keyword in it, make it relevant to a searcher and write it for humans, not search engines. If you want to have this 20-word meta description which accurately describes the page you have optimised (for one or two keyword phrases) when people use Google to search, make sure the keyword is in there. There is more likelihood it will be used by Google as your snippet description in SERPs.
For example, let’s say you were running the website of an online pet store. You might be wise to create one keyword grouping for all your dog-related products, then one for all of your parakeet-related projects, etc. The next step would be to segment each individual group into smaller subgroups (parakeet cages, parakeet toys, parakeet snacks) and then even smaller groups for each type of product (low-fat parakeet snacks, luxury parakeet snacks… you get the idea). Now your pet store can create individual pages optimized for each small keyword group.