Editing Cognitive load (section)

==Measurement==
As of 1993 Paas and Van Merriënboer<ref name=Paas1993/> had developed a construct known as relative condition efficiency, which helps researchers measure perceived mental effort, an index of cognitive load. This construct provides a relatively simple means of comparing instructional conditions, taking into account both mental effort ratings and performance scores. Relative condition efficiency is calculated by subtracting standardized mental effort from standardized performance and dividing by the square root of two.<ref name=Paas1993/>

Paas and Van Merriënboer used relative condition efficiency to compare three instructional conditions (worked examples, completion problems, and discovery practice). They found learners who studied worked examples were the most efficient, followed by those who used the problem completion strategy. Since this early study many other researchers have used this and other constructs to measure cognitive load as it relates to learning and instruction.<ref name="Paas et al. (2003)">{{cite journal |last1=Paas |first1=Fred |last2=Tuovinen |first2=Juhani E. |last3=Tabbers |first3=Huib |last4=Van Gerven |first4=Pascal W. M. |s2cid=16587887 |title=Cognitive Load Measurement as a Means to Advance Cognitive Load Theory |journal=Educational Psychologist |date=March 2003 |volume=38 |issue=1 |pages=63–71 |doi=10.1207/S15326985EP3801_8 |citeseerx=10.1.1.670.1047 }}</ref>

The ergonomic approach seeks a quantitative neurophysiological expression of cognitive load which can be measured using common instruments, for example using the [[heart rate]]-[[blood pressure]] product (RPP) as a measure of both cognitive and physical occupational workload.<ref name="Fredericks et al., 2005">{{cite journal |last1=Fredericks |first1=Tycho K. |last2=Choi |first2=Sang D. |last3=Hart |first3=Jason |last4=Butt |first4=Steven E. |last5=Mital |first5=Anil |title=An investigation of myocardial aerobic capacity as a measure of both physical and cognitive workloads |journal=International Journal of Industrial Ergonomics |date=December 2005 |volume=35 |issue=12 |pages=1097–1107 |doi=10.1016/j.ergon.2005.06.002 }}</ref> They believe that it may be possible to use RPP measures to set limits on workloads and for establishing work allowance.

There is active research interest in using physiological responses to indirectly estimate cognitive load, particularly by monitoring pupil diameter, eye gaze, respiratory rate, heart rate, or other factors.<ref name="Heard, Harriet, and Adams (2018)">{{cite journal |last1=Heard |first1=Jamison |last2=Harriet |first2=Caroline E. |last3=Adams |first3=Julie A. |title=A comparison of three measures of cognitive load: Evidence for separable measures of intrinsic, extraneous, and germane load |journal=IEEE Transactions on Human-Machine Systems |date=2018 |volume=48 |issue=5 |pages=434–451 |doi=10.1109/THMS.2017.2782483 |doi-access=free }}</ref> While some studies have found correlations between physiological factors and cognitive load, the findings have not held outside controlled laboratory environments. [[Task-invoked pupillary response]] is one such physiological response of cognitive load on [[working memory]], with studies finding that pupil dilation occurs with high cognitive load.<ref name="Granholm et al. 1996"/>

Some researchers have compared different measures of cognitive load.<ref name="Skulmowski & Rey 2017" />  For example, Deleeuw and Mayer (2008) compared three commonly used measures of cognitive load and found that they responded in different ways to extraneous, intrinsic, and germane load.<ref name="DeLeeuw and Mayer (2008)">{{cite journal |last1=DeLeeuw |first1=Krista E. |last2=Mayer |first2=Richard E. |title=A comparison of three measures of cognitive load: Evidence for separable measures of intrinsic, extraneous, and germane load |journal=Journal of Educational Psychology |date=2008 |volume=100 |issue=1 |pages=223–234 |doi=10.1037/0022-0663.100.1.223 |s2cid=4984926 |url=http://pdfs.semanticscholar.org/3808/8da333aa85e0bb5c72d5eff3404b4b74edcf.pdf |archive-url=https://web.archive.org/web/20190222114604/http://pdfs.semanticscholar.org/3808/8da333aa85e0bb5c72d5eff3404b4b74edcf.pdf |url-status=dead |archive-date=2019-02-22 }}</ref>   A 2020 study showed that there may be various demand components that together form extraneous cognitive load, but that may need to be measured using different questionnaires.<ref name="Skulmowski & Rey, 2020"/>