The term, ‘inquiry based learning’ means whatever the practitioner wants it to mean at any given time. So there is no way of knowing what any individual teacher is actually ‘doing’ in their classroom when they claim to be ‘doing' inquiry based learning. Other terms for much the same thing are Progressive, constructivist, discovery, hands-on, guide on the side, Whole Language, HOTS/higher order thinking skills, etc.
They can all be grouped as ‘minimal guidance’ and the entire philosophy is opposed to direct, explicit, systematic, teacher-directed instruction mapped to a common core with frequent testing to monitor progress. Therefore, it is not possible for a programme to consist of both inquiry based learning and explicit, systematic/synthetic, teacher directed phonics instruction unless someone is being misled somewhere along the track.
The following may be of interest.
Why minimal guidance during instruction does not work: An analysis of the failure of constructivist, discovery, problem-based experiential and inquiry-based teaching (PDF) by P. A. Kirschner, J. Sweller, and R. E. Clark, Educational Psychologist, 41(2), 75-86 (2006). (Also available here.)
From the abstract:
"Although unguided or minimally guided instructional approaches are very popular and intuitively appealing, ... these approaches ignore both the structures that constitute human cognitive architecture and evidence from empirical studies over the past half-century that consistently indicate that minimally guided instruction is less effective and less efficient than instructional approaches that place a strong emphasis on guidance of the student learning process. ... Recent developments in instructional research and instructional design models that support guidance during instruction are briefly described."
From the introduction:
"Disputes about the impact of instructional guidance during teaching have been ongoing for at least the past half-century. ... On one side of this argument are those advocating the hypothesis that people learn best in an unguided or minimally guided environment, generally defined as one in which learners, rather than being presented with essential information, must discover or construct essential information for themselves ... On the other side are those suggesting that novice learners should be provided with direct instructional guidance on the concepts and procedures required by a particular discipline and should not be left to discover those procedures by themselves ...
"The minimally guided approach has been called by various names including discovery learning ... problem-based learning ... inquiry learning ... experiential learning ... and constructivist learning ..."
From the conclusions:
"After a half-century of advocacy associated with instruction using minimal guidance, it appears that there is no body of research supporting the technique. In so far as there is any evidence from controlled studies, it almost uniformly supports direct, strong instructional guidance rather than constructivist-based minimal guidance during the instruction of novice to intermediate learners. Even for students with considerable prior knowledge, strong guidance while learning is most often found to be equally effective as unguided approaches. Not only is unguided instruction normally less effective; there is also evidence that it may have negative results when students acquire misconceptions or incomplete or disorganized knowledge."
(I think the following links are dead by the excerpts are all you really need.)
If It Quacks Like a Duck, It's Probably Baloney (April 2002) by Martin A. Kozloff, Distinguished Professor, Watson School of Education, University of North Carolina in Wilmington. Dr. Kozloff starts out with the disarmingly succinct realization that
... parents, consumer organizations, state legislators, serious educational researchers, and even federal agencies have tied together two simple facts:
1. Too many students aren't learning much.
2. This may have something to do with instruction.
If instruction is failing, then what's taking it's place? Dr. Kozloff answers by dissecting each of some of the most endemic and worrisome buzzwords floating around the education industry, including:
"Developmentally appropriate practices."
"It is best when the teacher is a facilitator rather than a transmitter of knowledge. It is best for students to discover and construct knowledge on their own."
"Homogeneous grouping for a short time each day for certain subjects based on students' current skills is bad. It lowers self esteem and creates tracks. It is discrimination."
"It is better for teachers not to correct students' errors immediately. Error correction makes students dependent on the teacher. Therefore, students should discover errors themselves and learn to correct them."
"Having students frequently practice skills is not an effective way to foster mastery and self-esteem. Frequent practice inhibits creativity and is boring."
"It is best for teachers to create their own curricula and lesson plans, rather than follow programs. Following programs disempowers teachers and stifles creativity."
"Romancing The Child" by E. D. Hirsch Jr., Education Matters, Spring 2001. Hirsch criticizes the "Romantic" notion of how children learn, and passionately presents the case for practical, common-sense, validated methods. Excerpts:
"The Disney Corporation's Celebration School sounded like yet another fairy tale from the creators of the Little Mermaid and the Lion King. It was supposed to be the ideal school, set in Disney's newly created Florida community, Celebration. According to the New York Times, the school was to follow the 'most advanced' progressive educational methods. ... Such methods, although they have been in use for decades, have rarely worked well. The Celebration School was no exception. As the Times headline put it, there was 'Trouble at the Happiest School on Earth.' The Times article began, 'The start of the school year here is just a few days away, so it was no surprise that there was a line of parents at the Celebration School office the other day. But the reason for the line was: they were queuing up to withdraw their children.' Parents said they were dissatisfied with the lack of clear academic goals and measures of achievement, as well as with the lack of order and structure that accompanied the progressive methods.”