Based on the historical analysis and five other fundamental factors we measure, we have a Fairly Valued stance at this time as we downgraded it in early March due to valuation concerns.

FORBES: Align Technologies Takes One In The Teeth

The key difference is that clinical trials are much more rigorous, and as much as possible rely on objective, quantitative analysis to measure improvement, as opposed to field trials, which are more reliant on patients' subjective reactions.

FORBES: Magazine Article

The first is regression analysis, which seeks to measure whether an outcome, such as wage differentials between blacks and whites, is correlated with race once all other relevant factors, such as education and experience, are taken into account.

ECONOMIST: Race, sex and the dismal science | The