help me write in a simpler way: Formative Evaluation: Formative evaluation is conducted during the process of learning or program implementation. It provides ongoing feedback to help improve and refine the learning or program while it's still in progress. It's like a checkpoint or progress report that allows for adjustments and improvements to be made along the way. Formative evaluation is often informal and can be as simple as a teacher asking questions in class to gauge understanding or a program manager checking in with staff to see how a new system is working. Summative Evaluation: Summative evaluation, on the other hand, is conducted after the completion of a learning period or program. Its purpose is to assess the overall effectiveness and impact of the program or learning. It's like a final exam or a program review that measures the outcomes against the objectives. Summative evaluation is often more formal and structured, and the results are used for grading, certification, or decision-making about program continuation or expansion