Decline in engagement metrics, due to nav changes vs. content changes

[ahw]

With improvements in our rankings, we are seeing adverse changes in our measures of engagement. My gut reaction is to believe we are attracting more unqualified traffic, thus higher bounce rates, declines in pages/visit and time on site (approx 15%, 15%, 25%, respectively).

While recent improvements in navigation might have contributed  to these engagement declines, do you have any suggestions how best to determine whether these declines are due to nav changes vs. due to copy/content issues?  There's been no change in copy content during this period.

Thanks.

[BryanCasson]

It would be best to use A/B testing (by Google) to figure out where the traffic changes are taking place. This is done by using a utm_content variable in the URL tag.

Here is the link: http://support.google.com/googleanalytics/bin/answer.py?hl=en-GB&answer=55589

If you are running Adwords then the Website Optimizer is a good place to start.