Indeed, the marginal productivity gains observed with QE at a global level become statistically significant in specific conditions, depending on the length (between 5 and 20 words) of the source sentences and the quality (0.2<HTER≤0.5) of the proposed MT suggestions (our third contribution).
to check this hypothesis we compared the HtER scores obtained in the two conditions (colored vs. grey flags), assuming that noticeable differences would be evidence of unwanted psychological effects.