Sentences with phrase «difference by the standard deviation»

Not exact matches

They measure changes in analyst earnings forecast dispersion (standard deviation divided by mean) based on data from I / B / E / S as the difference between current dispersion and dispersion two months ago.

«Identifying VXX / XIV Tendencies» finds that the Volatility Risk Premium (VRP), estimated as the difference between the current level of the S&P 500 implied volatility index (VIX) and the annualized standard deviation of S&P 500 Index daily returns over the previous 21 trading days (multiplying by the square root of 250 to annualize), may be a useful predictor of iPath S&P 500 VIX Short - term Futures ETN (VXX) and VelocityShares Daily Inverse VIX Short - term ETN (XIV) returns.

But unlike Chingos and West, they found t teachers who chose the hybrid plan out - performed teachers who chose the defined benefit only by about 2 to 3 percent of a standard deviation, an effect that would be similar in magnitude to the difference between a beginning teacher and a teacher with one to two years of experience.

The impact on student math and reading achievement differed by about 20 percent of a standard deviation, a difference which the authors note is «striking, roughly equivalent to having a teacher who is at the 16th percentile of effectiveness rather than at the 50th percentile.»

The overall grade for each state was determined by comparing the difference with the standard deviation from the average for all states for all four years on the tests for which the state reported proficiency percentages.

In Hyderabad, students attending recognized and unrecognized private schools outperformed their peers in government schools by a full standard deviation in both English and math (after accounting for differences in their observable characteristics).

Cohen's d is defined as the difference between two means divided by a standard deviation of the pooled groups or of the control group alone.

In math, the differences in gains made by African Americans and Hispanics at AYP schools and non-AYP schools are 11 and 12 percent of a standard deviation, respectively.

By 2000, math scores were roughly 0.3 standard deviations higher than predicted, an improvement about one quarter the size of the difference in math performance between Chicago students in consecutive grades in 1995.

We find that black students in North Carolina do better on reading tests when matched with same - race teachers (by about 3 percent of a standard deviation), but there are no differences in their math performance.

The effect size of this difference is.81 and was computed by subtracting the mean of the comparison group from the mean of the experimental group and dividing by the standard deviation of the comparison group (Cohen 1977).

The MSLP anomaly difference of Tahiti minus Darwin, normalised by the long - term mean and standard deviation of the MSLP difference (Troup, 1965; Können et al., 1998).

If you look at that chart, the normalizing by dividing by standard deviation and then taking the difference, is not like super advanced math.

From the tree ring width differences one can see that the variations are influenced by the younger tree ring ages being bigger and tending to give a larger standard variation, but not entirely as the smaller older tree rings in some of the trees from the second half of the difference series had standard deviations larger than the younger larger rings from the first half of the difference series..

Actually, I think we can use this model - obs comparison to crudely estimate possible magnitude of internal variability by taking the standard deviation of the difference between modelled and observed trends.

Note the implicit swindle in this graph — by forming a mean and standard deviation over model projections and then using the mean as a «most likely» projection and the variance as representative of the range of the error, one is treating the differences between the models as if they are uncorrelated random variates causing > deviation around a true mean!.

We also check the validity of the rank histogram approach by comparing the model - data difference with the ensemble spread through calculating the root mean square model - data difference (RMSE), and the standard deviation of the ensemble (SD).

We implemented unadjusted and adjusted analyses (potential prognostic factors listed in table 2) of the outcomes (all quantitative) by using random effects linear regression models fitted by maximum likelihood estimation to allow for the correlation between the responses of participants from the same maternal and child health centre.29 We present means and standard deviations for each trial arm, along with the mean difference between arms, 95 % confidence intervals, and P values.

We calculated effect sizes by dividing the mean difference between the trial arms by the pooled standard deviation.

Between - group effect sizes were determined by measuring the difference in magnitude of change between treatment and comparison groups in units of standard deviation.

An effect size refers to the difference in mean scores between 2 populations (eg, children referred with ADHD vs nonreferred children) divided by an estimate of the individual standard deviation.