T-GEM is a gem:  pH + phet = phew!

T-GEM- From the readings

T-GEM involves using Technology to promote the cyclical pattern of learning which enhances teacher–student interactions where the learners: Generated, Evaluated, and Modified (GEM) hypotheses.  Khan (2007) believes that sustained use of the GEM cycle contributes to students’ engagement with scientific inquiry and model construction and manipulation.  GEM has an inquiry focus which prompts exploration of scientific concepts using methodologies similar to those of ‘real’ scientists and technology can further enhance that inquiry focus.  All of the 12 aspects of inquiry learning identified by Khan (2007) can be integrated using T-GEM:

• identifying a problem and gathering information,
• making predictions,
• making sense of observations and finding patterns in information,
• using analogies and physical intuition to conceptualize phenomena,
• analyzing and representing data,
• postulating potential causal factors,
• working with evidence to develop and revise explanations,
• generating hypothetical relationships between variables,
• evaluating the empirical consistency of information,
• formulating and manipulating mental or physical models (modeling),
• coordinating theoretical models with information, and
• sharing what has been learned from the inquiry with others.

T-GEM as described by Khan (2010) is a dynamic model-based inquiry process which challenges existing mental models while inquiring about a phenomenon.  These mental models are tested using “abductive reasoning with visual representations, thought experiments, and analogies” (Khan, 2007, p.3).  The ultimate goal of this approach is to empower students to think about chemistry at a molecular level before they build relationships and create large scale meaning using simulations that challenge existing mental models.  Since there is currently such limited support regarding inquiry in curriculum documents, using the T-GEM approach has the potential to enable students to learn content through inquiry processes which utilize technology enhanced learning environments.  Khan (2010) uses TPACK -Technological Pedagogical Content Knowledge-a promising theoretical teaching framework which outlines the relationship between the teacher’s:

• Technological Content Knowledge,
• Technological Pedagogical Knowledge, and
• Technological Pedagogical Content Knowledge.

 This framework provides a shared vocabulary to describe how teaching with computer simulations can enable teachers to make explicit connections between the use of ET and the curriculum content.  Computer simulations are so useful for challenging mental models because they allow the learner to manipulate variables to determine different results.

Technology and G-enerate: -the technology can support students in processing large data sets through visual representations and to generate patterns, identify trends and relationships between variables

Technology and E-vaulate:  In technology can support the design of new tests for hypotheses, to select-change-reselect variables to make comparisons, generate graphs and even allows consideration of extreme cases

Technology and M-odify:  digital computer simulations can allow students to manipulate variables in many different ways while observing changes and as a result of this interaction develop their critical thinking skills. Modifying hypotheses using technology prompts students to summarize the relationships in their mental models.

Thoughts on the affordances of ChemLand

Chemland simulations have the potential to be used with the T-GEM approach as well as for promoting student engagement.  The visual, manipulative nature of the simulations allows students to generate hypotheses, evaluate their choices and modify based on results.  This process provides learners with the opportunity to build knowledge at a conceptual level first before making meaningful relationships.  This promotes discovery learning and employs constructivist features (learner-centered, knowledge building to make meaning, inquiry process) and creates a cognitive disturbance which requires a solution.

Why is pH a challenge to teach?

Teaching pH on a conceptual level is very challenging as students can understand what it means for pH to be low or high (ie. acidic or alkaline) but they don’t understand why.  There are misconceptions of what pH even stands for.  pH being a measure of th e number of H ⁽⁺⁾ ions in a solution is difficult to grasp.  Learning about relationship between H₃O⁺ and OH^– ratios and how to calculate the concentration in mol/L is even more difficult.  

Applying T-Gem to Teaching pH

T-echnology: Obtain simulation atà  http://phet.colorado.edu/en/simulation/ph-scale

G-enerate:  predict if a liquid is acidic or basic, rank the order of liquids in relative order of acidity, visualize the relative number of hydroxide ions and hydronium ions in solution, create a description of a new liquid, Calculate concentrations of hydroxide and hydronium ions at a given pH. 

E-valuate: check predictions using the model, switch between logarithmic and linear scales, investigate whether changing the volume or diluting with water affects the pH, use graphs to explain properties of new liquid

M-odify: compare qualitative relationships between pH and concentration of hydroxide and hydronium ions using the values and graphical / pictorial representations shown in the simulation  (ie. the relationships between:   pH and hydronium ion concentration, hydronium ion concentration and hydroxide ion concentration, pH and hydroxide ion concentration), predict (qualitatively and quantitatively) how increasing or decreasing the volume of a particular liquid affects its pH, concentrations of hydroxide and hydronium ions, and moles of hydroxide and hydronium ions. 

References

Khan, S. (2007). Model-based inquiries in chemistry. Science Education, 91(6), 877-905.

Khan, S. (2010). New pedagogies for teaching with computer simulations. Journal of Science Education and Technology, 20(3), 215-232.

 (some ideas taken from http://phet.colorado.edu/en/contributions/view/3022)