Each page is rated for OnTime Delivery, by our rule based rating system. "On Time" delivery for Web pages is a very subjective concept. (For most people the Web is never fast enough :-) We have put a lot of effort in the last eight months into defining this fuzzy concept in a measurable way.
First we divide page deliveries into "Fast" and "Slow" (Explanation) and take the average for each. If this difference (called the "spread") is less than 5 seconds, we rate the page as GOOD. Our beta test analysis showed that this represents good performance even for small pages.
Next we look average "spread" for all pages this week. We then compute what the spread for your page would have been if it matched the average, and call this the "Expected spread". Using this weeks average in the computation prevents your page rating from being affected by a poor week on the Web or at our service provider. Your page is rated as GOOD if the actual spread is significantly better than the expected spread. That is:
Another "Threshold" factor is used to determine if OnTime Delivery is POOR. The "Threshold " factors are adjusted to rate about 20% of the pages as POOR, and 30% as GOOD.
Pages that are neither GOOD nor POOR are rated as OK. Because the "Threshold" factor is set relative to all the pages we monitor, the standard for OK pages will rise over time with rising Web delivery performance. We believe your clients will rate your site relative to others on the Web, so this rising threshold is quite realistic.
The "OnTime Delivery" rating tells you how consistently your pages are being delivered. This is very useful for fixed size pages. If your page is generated dynamically with varying size, it will never get a GOOD rating. You should look at the average delivery time to see if this is appropriate for the information your page is conveying to your reader.
Return to Delivery Report description.