Abstract
The main goals of this project are; to develop and assess the effectiveness of learner centered activities for introductory astronomy that focus on solar system topics and; to test the methods of learner-centered instruction themselves through the implementation of these activities and their assessments. The intended end of the project is to have developed entire solar system :""unit"" consisting of learner-centered activities on solar system topics that have been tested for their effectiveness.
Since 2000, many resources for active and collaborative learning in introductory astronomy have been developed. This is especially true for two of the four the main sections of a traditional introductory college astronomy course, the observed motions in the sky and light, the Sun and stars. There is currently considered to be a dearth of activities pertaining specifically to solar system topics, also considered one of the four main sections of a traditional course. For instance, the leading Lecture-Tutorial (LT) workbook (Prather et al., 2007) has 38 LTs, 14 of them, 37% are about topics related to the observed motions in the sky and 16, 42% are topics related to light, the Sun and stars. Of the remaining 8, only 4, 11%, are about topics traditionally covered in a solar system unit, one each on the Earth's surface, the formation of the solar system, the size and scale of solar system objects and extra solar planets. There are tutorials on planetary motion and gravity, but these are topics generally covered in the earlier motions and history unit. The last 4 LTs are about galaxies and cosmology.
Research investigating student pre-instruction beliefs and reasoning difficulties in cosmology, considered the fourth main section of a traditional astronomy course, is also underway as is the development and assessment of instructional materials. (CATS projects/ Research on Students Beliefs and Reasoning Difficulties related to Cosmology
http://astronomy101.jpl.nasa.gov/cats/projects/)
Another reason for development of more material covering solar system topics is for research to better understand student learning in these areas. An assessment instrument the Solar System Concepts Inventory, SSCI that is under development and preliminary testing will eventually be used for this purpose. The availability of more material to assess will aid in the validation of the survey and then the survey itself will in turn aid in the development of even more new materials. (CATS projects / Solar System Concept Inventory (SSCI) & Solar System Lecture-Tutorials Project,http://astronomy101.jpl.nasa.gov/cats/projects/)
Assessment instruments on light and spectra, the Light and Spectroscopy Inventory, LSCI (Bardar et al., 2007), and stellar topics, the Star Properties Concept Inventory, SPCI (Bailey, 2008), already exist and have been field tested (Bardar, 2008), used in research (Prather et al., 2008, Prather et al. 2009), and used to test instruction materials (Barder & Brecher 2008, LoPresto & Murrell, 2009) as does a good amount of instructional material on these topics. (Prather et al., 2007). Assessment instruments on cosmology are also under development. (Wallace et al., 2011).
The activities developed, implemented and assessed for this project, in the order that they were assigned during a solar system unit, are;
1-The HFCC Solar System Walk
2-Comparative Planetology
3-Formation of the Solar System
4-Extra-Solar Planets
5-Comets
6-Surface Conditions of Terrestrial Planets
1-Planetary Geology
2-Planetary Atmospheres
A pilot research project that was designed and undertaken to test the viability of this project consisted of using active and collaborative instructional materials that were already in existence on other topics and testing them with an already existing and established assessment instrument. Based on the number of Lecture-Tutorials (LTs) available on the subjects of light, the Sun and stars (Prather et al., 2007) and the existence of an already established concept inventory, the Star Properties Concept Inventory (SPCI) (Bailey, 2008), light, the Sun and stars, usually the third 'unit' of a general education introductory astronomy course, was chosen.
The experimental design of the different studies in this project is similar to that of the pilot project. In general, students were given pretest and posttest assessments so gains in groups receiving different methods of instruction could be compared. The scores of students who did the activities were compared to students that did not do the activities and were rather taught the same topics through more traditional lectures.
The assessment instrument used was the Solar System Survey, 25-item multiple-choice items on solar system topics developed and validated for this project to test the instructional materials developed and the instructional methods they employ.
In efforts to minimize instructor bias and the Hawthorn Effect (Hake, 1998, from Slavin, 1992) different instructors involved in the studies were assigned to teach different sections both by lecture and by learner-centered methods. Also, in the final trials of each study, the author taught none of the sections involved.The statistical significance of results were evaluated in two ways. When the performance of two groups on a set of assessment questions was being compared, the average score of each group and the standard error were calculated. The standard errors were considered the error-bars around each average. The less overlap in the error bars, the more significant the result. If there was no overlap the difference in the average scores of the two groups was considered statistically significant.
When the results of different groups on specific assessment items were compared the statistical significance of results were evaluated by chi-squared tests with 2 x2 contingency tables. The numbers of students giving correct and incorrect responses in each group were put into 2 x 2 contingency tables that were used to calculate. P-values. The lower the P-value the more significant the result, P=0.05 being considered the maximum value for a significant result.
