Aussie Web Analyst

So you have your basic metrics and you know the best ways of giving the numbers some meaning. What then is the appropriate time period to use in order to understand performance when looking at this data? Should it be day, week, month, quarter, year or something different altogether?

My first belief is that a time period of longer than a month should just not be used. I am reliant on trending in order to understand performance and for periods of greater than a month, there are too many factors affecting the numbers for them to be that meaningful. Instead, when required to produce a performance review over a longer time span, data should be trended at monthly level and, if need be, average monthly numbers can be used.

This just leaves daily, weekly and monthly time periods. All are useful but they do provide different levels of information.

Monthly Data

Web analytics cannot operate in a silo and since most companies have all their financial reporting produced on a monthly basis, web performance reporting should be available in the same time period. Beyond this, the strength of monthly data is that it provides big numbers over a lengthy period of time meaning good or poor performance is more visible/obvious.

However the problem with months is that they contain different numbers of days and different days of the week, with both of these being basic factors that impact on reported performance during a time period. The simple solution is knowing and understanding these impacts and being able to explain how they affect the numbers to your managers.

Weekly Data

This should be the basic time period used by any web analyst. Their first task on a Monday morning (or whatever the first day is for a new week for their company) should be to click a button to update their weekly reports and to cast their eye over the performance for the week to see if anything looks interesting. If any numbers look high or low, they should then be spending a couple of hours (or whoever long it takes) running ad hoc reports in order to understand why.

I feel that looking at a fairly complete set of metrics on a weekly basis strikes a nice balance between looking at data too often and not often enough. If the business is only looking at their data in detail once a month, they are simply not able to react fast enough in case of something changing. However, there is a danger in overanalysing data and being too sensitive to random fluctuations. There is no point in an analyst spending a large chunk of every day examining the web traffic in detail for the previous day if there were no changes to the website or marketing.

Daily Data

So having said that, why do I advise daily data as being useful? While I believe in a set of reports at weekly and monthly level, at daily level I would have only one or two metrics, potentially segmented, that are looked at. The obvious one is total interactions (usually page views) for the day, compared against a forecast total or, if that is not available, against the same day in the previous week. If the percentage change is within a certain range, move on with your work for the day. But if something has happened on that day, as should be immediately obvious just by looking at this one number, this is a clear alert that the data for that day needs to be interrogated further.

Tags: Time Periods, Web Analytics