With Google Analytics, a hit is ANY request sent to the GA data collection system. This includes pageviews, events, custom variables, measurement protocol uploads, etc.
This is what is defined as a pageview and I think covers your questions, ultimately.
Does Google Analytics count another page view for index.html?
A pageview is recorded every time a page is viewed. Or, more technically, a pageview is recorded every time the Google Analytics pageview tracking method is executed. When a visitor hits the back button, a pageview is recorded. When a visitor hits refresh, a pageview is recorded. Every time a page is opened in the browser, regardless of whether it has been cached, a pageview is recorded.
I hope an external referrer is only counted once in a session, so the back-navigation will not count as another visit from google?
Counted Once Per Session: The original referrer is the first referrer in a visitor’s first session, whether internal, external or null.
- A visit consists of a series of pageviews that a single visitor makes during a period of activity. A visit ends after the visitor either closes the browser, clears cookies, or is inactive for 30 minutes.
But what will be in the previous page path for that visit?
Can it make the connection index→page1→index? or is the navigation path broken?
Does google use direct as the source?
Since Google Analytics cannot tell ahead of time what page you will be visiting next, it simply keeps a two page relation on every page visit. The current page you are on (Next Page Path), and the page you were on before getting to the current page (Previous Page Path).
For instance if you come into a site on a home page, while you are on the home page, you will have your Next Page Path set as the home page. The value of the Previous Page Path in relation to the current page you are on, is always the page you visited before coming to the current page, or it will state that it was an entrance. This leaves us with the simpler structure below:
Previous Page Path → Next Page Path
By setting up a custom, Flat Table report with both Previous and Next Page Path as the dimension choices you can use the relation between these dimensions to gather some very useful information. If you’re curious which page users come from to get to a certain page or which page users go to after visiting a certain page, than this report is perfect for you.
By using the advanced search function, you can set the Previous Page Path dimension to the page you’d like more information on. With the Previous Page Path set to a specific page, the Next Page Path dimension values become a report of pages that users visited after that page. Alternatively, if you set a specific page as the Next Page Path, the Previous Page Path value becomes a report of the pages users visited before coming to the specified page.
The Next Page Path and Previous Page Path reports allow you to see common user paths through pages on your site. They are very powerful when understood and used properly. With a little effort, these reports can help you determine if your users are moving through your site as expected, allowing you to improve the user experience in ways that were not possible before.
For all analytic definitions and effects, or causes. You can learn more here: http://www.analyticsmarket.com/blog/google-analytics-definitions