Effects of self-experimentation during practical classes on student learning

Introduction

Several studies have shown that active learning is more attractive and generates more interaction than passive methods^1–4. Among active-learning strategies, some studies^5,6 point out that practices that mimic routine activities increase learning compared to practices without this characteristic. For example, the use of virtual patients by medical students can increase their degree of learning⁵, and the use of case-based learning increases deep learning, the involvement of students, and their interest in content^6,7. Problem-based learning (PBL), which frequently involves simulations of real situations (e.g., diagnosis of a hypothetical patient with some symptoms), has been an important tool to improve knowledge retention^8–10. Another active-learning strategy that may increase academic achievement is the use of self-monitoring and self-assessment methods^11–14. For example, after answering questions of a knowledge test, when students are allowed to see their colleagues’ answers and revise their own answers, the number of correct answers increases¹⁵. Evidence indicates that practices that involve both routine activities and self-monitoring promote even greater attraction of students for classes^16,17, as well as greater interaction during classes¹. A previous study submitted university students to the ingestion of pizza and pasta and the measurement of biochemical parameters¹⁸. This method made it possible to cover important topics of metabolism in the final exam and to show how the metabolic machinery of the human organism reacts to different diets. In the period when this method was applied, the grades were higher than in previous periods. However, there was no control group, which hindered assessing the real efficiency of this method¹⁸. Other studies in which the students used their own body (self-experiments) did not investigate the influence of this practice on learning¹⁹. The few reports on self-experiments frequently involve activities that are not part of the students’ routine²⁰.

As far as we know, there are no studies on the impact on learning of practical classes using the students’ own bodies in routine situations. A experiment based on the measurement of the academic achievement of students submitted to self-experiments during practical classes compared with students who attended regular practical classes (control) could help assess the influence of self-experiments on student learning. The present study shows a new active-learning method, which is more efficient than the methods commonly used in classrooms.

The present study aimed at analyzing the impact of self-experiments under conditions that mimic everyday situations – fasting and ingestion of carbohydrate-rich oral solution with glucose and fructose – on the achievement in exams of university students of health sciences and their degree of motivation and satisfaction in carrying out those experiments.

Methods

Results

Learning indicators

The objective of applying two tests about the topics of Cell Biology was to analyze the impact of self-experiments under conditions that mimic everyday situations – fasting, ingestion of water and carbohydrate oral solution ingestion (glucose or fructose) – on the achievement of university students of health sciences. In the test that preceded the experiment carried out in the present study, the grades of the students that participated actively and of those that only observed were similar (p > 0.05). In the test applied after the experiment, both groups reached higher grades (p < 0.01), but the individuals that participated actively in the experiment obtained higher grades than those that only observed it (p < 0.05; Figure 1 and Table 1). Test results for each student are available as Underlying data²¹.

Figure 1. Effect of self-experiments on learning.

Comparison of achievement in tests between students who participated actively in the experiments and students who only observed them. *p < 0.05.

Table 1. Descriptive statistics of the tests before and after self-experimentation by observer and active groups.

Test	Active experiment participant?	N	Average	SE	1ºQ	2ºQ	3ºQ	p-value1
Before self-experimentation	No	38	6.49	0.18	5.50	6.50	7.00	0.074
	Yes	33	6.92	0.20	6.50	7.00	8.00
After self-experimetnation	No	38	7.33	0.24	7.00	7.00	8.00	0.017
	Yes	33	8.11	0.23	7.00	8.50	9.00

¹ Mann-Whitney test. SE, standard error.

Considering the differences between the subgroups of the students who participated in the experiment, there was no significant difference in grades among the subgroups fasting, glucose, and fructose (p > 0.05). Considering the differences within subgroups, only the students of the glucose and fructose groups showed an increase in their grades after the experiment (p < 0.05; Figure 2, Table 2).

Figure 2. Effect of self-experiments on learning.

Comparison of achievement in tests by students who participated actively in the experiment among the groups fasting, glucose, and fructose *: p < 0.05.

Table 2. Frequency and descriptive statistics for the active group.

Variables		Participants, n†	%†
Total		33	100
Sex	Female	27	81.8%
	Male	6	18.2%
Motivation	Low	1	3.0%
	Medium	8	24.2%
	High	24	72.7%
Learning is deeper in practical classes	No	2	6.1%
	Yes	31	93.9%
Practical classes are more interesting than theoretical classes	No	3	9.1%
	Yes	30	90.9%
Practical classes are essential for learning	No	1	3.0%
	Yes	32	97.0%
Blood glucose levels
Glucose group, mg/dL*	Fasting	86.0	[84.5; 93.0]
	30 min	141.0	[120.0; 146.0]
	120 min	103.0	[99.5; 119.5]
Fructose group, mg/dL*	Fasting	87.0	[69.0; 90.0]
	30 min	96.0	[91.0; 100.0]
	120 min	88.0	[84.5; 95.0]
Fasting group, mg/dL*	Fasting	89.0	[82.0; 92.5]
	30 min	98.0	[90.5; 100.0]
	120 min	88.0	[85.0; 95.0]
Age, years*		26.0	[20.0; 33.0]
Height, m*		1.6	[1.6; 1.7]
Motivation to participate in practical classes*		10.0	[7.0; 10.0]

†Unless indicated.

*Quantitative variables (median, interquartile range).

Discussion

This study showed that students that provide blood samples for biochemical experiments in practical classes obtained higher grades than students that only observed the experiment. After the application of this teaching method, the group of students that participated actively in the practical classes (by providing blood samples) obtained higher grades than the group of students that only observed the experiment. However, both groups increased their grades, as shown by the learning assessment tests. This increase in learning corroborates the results generated by several authors, which indicate the efficacy of active-learning methods and several studies that showed an increase in learning through the use of active learning^22–25. Nevertheless, most studies whose authors affirm that active-learning methods are better than others are based on theory, as they do not show experimental results or do not use proper control groups²⁶. Several studies with a proper control group did not observe differences in learning between active-learning methods and passive, traditional methods^4,27,28. Finally, some studies show that the use of active learning methods can even result in lower grades^29,30.

These differences in results obtained with different learning methods suggest that other factors affect the efficacy of these methods and can occur regardless of the teaching method being more or less active. One of those factors seems to be the teacher’s behavior. For example, a teaching improvement tends to occur when teachers propose problems and questions, and stimulate a working atmosphere that give students freedom to take risks, make mistakes, and learn from their own mistakes³¹. Indeed, the attractiveness of educational activities developed is higher in the physical presence of the teacher^32,33. Hence, we expect the learning strategies that provide the best learning atmosphere to be also the most efficient. The most striking result of the present study was the higher increase in grades of the group of students that participated actively in practical classes compared to the group of students that only observed them. This finding corroborates positive results of methods that involve self-assessment of learning by the students¹⁵. To our knowledge, this is the first study that shows that a teaching method in which the students assess their own body promotes deeper learning. Other studies have already showed that classes involving education of students using their own body as a subject can bring benefits^19,18, but s no study has used control groups. One explanation for this phenomenon would be that this method ensures deep compulsory involvement of the student, which could increase their degree of attention and focus in the experiment and avoid distractions.

The results obtained by the students during the practical class could show them how the human organism responds to common everyday situations. In the groups that ingested carbohydrates, there was an increase in blood sugar and this increase was higher in the group that ingested glucose than in the group that ingested fructose. Similar to our experiment, several studies intended to measure blood sugar at the ingestion of glucose and fructose solutions^34,35,36, and the everyday diet of people^19,18. The lack of difference in grades in the test after the experiment among the subgroups that participated actively in the experiment (fasting, glucose, and fructose) indicates that the collection of one’s blood increases information comprehension and retention about the entire practical class and not only the result of one’s own organism or one’s own group. Hence, those that ingested glucose understood what occurs when one ingests fructose or remains fasting. This method may be more attractive to the students and may drive their attention The data of the analysis of the three groups that participated in the experiment also corroborate that. The significant increase in the grades only in the subgroups that ingested glucose and fructose and not in the grades of the subgroup that remained fasting suggests that the ingestion of solutions helped the students reach deeper learning compared to the students who only donated blood. The method used in the present study involves different forms of active participation and at the same time a study about the students’ own bodies at everyday situations and provides an active visceral learning.

Surprisingly, the motivation and satisfaction in doing experiments, which was measured through a questionnaire, did not differ among subgroups. This result was unexpected, as more active learning methods tend to generate more interest^1,2. However, the lack of difference may be due to the participation, as observers, of the students that did not use their own bodies in the practical classes. This explanation is corroborated by the fact that over 90% of the students answered that practical classes are more interesting and provide deeper learning. Other studies showed different values. For example, although medical students and residents subjected to active learning are more engaged and interact more with each other (43%) and with the teacher (57%), they reported lower perception of the objectives of learning⁴. In another study, most medical students studying clinical biochemistry (73%) opined that an active-learning method was more motivating, aroused the interest in the subject, and increased learning⁶. Another explanation for the results of our study is a possible insensitivity of the questions used in the questionnaire to subtle perceptions of students. Maybe the application of qualitative questions could better define the relationship between motivation and teaching method.

We conclude that active learning, in which the students use their own organism and blood in practical classes, can increase their grades in knowledge tests. This method led to an increase in learning compared to the control group, which only observed the experiments. In addition, the analysis of the three subgroups that participated actively in the experiment showed that the students who ingested glucose and fructose solutions had a significant increase in their grades, whereas those students who remained fasting did not. Such a difference suggests that a method that combines two different strategies, active learning and self-assessment, increases attention. The teaching tool showed in the present study is a positive alternative for university students in health sciences.

Data availability