First, if you contact admissions, they will not take away your acceptance for wanting to change your major. You cannot offically request to change your major until after your first quarter. You then sign a ICMA agreeement which outlines what you need to do to change into the new major and what requirements you need to meet. If you do not fulfill the ICMA, then you cannot change your major.
Here is some more information and an article about changing majors.
http://mustangnews.net/the-major-truth-cal-polys-change-of-major-policy/
Applies to matriculated undergraduate students at Cal Poly wishing to change major. The “target” major is the major into which a student wishes to transfer.
Policy Statement
Cal Poly students are required to declare a major at the time of application. Some students find that their interests and abilities lead them in a different direction. The university must offer a transparent and timely process for all students who seek to change majors.
Process
I. General Guidelines
A. Minimum Time at Cal Poly
Students must complete at least one quarter at Cal Poly before requesting a change of major.
B. Basic Criteria that may be used in advising for determining Target Major Options
All academic departments should give careful consideration when determining target major options. The following criteria may be considered:
The majors for which the student was eligible at time of admission,
College academic record (e.g., GPA, coursework, etc.), and
Remaining coursework and the student’s ability to complete degree requirements in the new major within the published unit maximums for that major.
C. One Chance to be Accepted
Students who enter into an individualized change of major agreement (ICMA) and do not complete the ICMA requirements will not be eligible to request that major again later in their career at Cal Poly.
D. Completion of Change of Major
The change of major will be approved once the student has successfully met all of the requirements of the ICMA.
E. Timeframe
The ICMA must be feasible to complete and be completed in no more than two quarters.
F. Publication of Change of Major Criteria
As applicable, department’s web sites should post the minimum criteria required of all students to change major into their program including timelines.
G. Impaction Constraints
Per the Office of the Chancellor’s The California State University Enrollment Management Policy and Practices, other admissions requirements for all transfer students (internal and external) entering the target majors on impacted campuses must be the same (e.g., portfolios, auditions, etc.).
H. Academic Standing
A change of major agreement will be void if a student is academically disqualified prior to the completion of the agreement.
II. Requesting a Change of Major
Meet with current adviser to review major options and talk about career paths. Consider, also, consulting with Career Services, other advisers, and faculty and/or department heads/chairs in both current and target majors.
Meet with the department head/chair or designee in the target major to determine the likelihood of success in the new major.
Review the curriculum requirements for the target major.
If the target major is not a good fit for the student, the student will be advised to look at other options.
If the student receives a positive assessment based on consideration of the basic criteria outlined in Section I-B (above), and it is clear that he/she can complete degree requirements in the new major within the unit maximum (unit maximum is 24 units above program requirements), then an ICMA will be developed (see below).
III. Individualized Change of Major Agreement (ICMA)
The change of major will be approved once the student has successfully met all of the requirements of the ICMA. The ICMA will cover no more than two quarters. The ICMA may include the following components:
Maximum of three specified courses or 12 units in the target major.
Additional courses and/or units to allow the student to meet minimum progress standards and complete degree applicable units in both majors, whenever possible (e.g., GE courses or electives a student could use to meet degree requirements in both current and target majors).
GPA requirements, as determined by the department (e.g., overall/term GPA, GPA in major-specified courses, GPA in past two quarters).
If applicable, specific steps to be met to resume good academic standing status.
General Information
As much as possible, entering students are encouraged to make careful and informed decisions about the initial application to their declared majors. All majors at Cal Poly are impacted and it will be difficult to change into some majors despite a student’s best efforts. Nevertheless, sometimes students will find that their interests, abilities, or talents will take them in a different direction than they had identified when they originally applied to Cal Poly and they may seek to change to a different major. Depending on the degree of impaction of the target major (i.e., the relationship between the number of applicants to the major and the number of places available), there might only be a few spaces available for change of majors, or no spaces at all. Students who are unable to change into their desired majors might also need to consider applying to another university in the major of their choice.
If a student makes the decision to change major, doing so early in the academic career will better allow a student to make degree progress in a timely manner and stay within the university’s minimum progress to degree standards; major changes late in the academic career will be restricted by the university’s minimum progress standards, including the unit maximum.
All students, whether lower division (those with fewer than 90 Cal Poly units) or upper division (those with more than 90 Cal Poly units or 90 transfer units), intending to change majors must demonstrate that they can complete the new major within the minimum progress standards and the unit maximum set forth by the university. This is likely to be a greater challenge for upper division students, who will have fewer remaining degree requirements. Further, students need to be aware that not all departments can accommodate upper division change of majors.
Good Luck with your decision. My older son was accepted to SLO 2 years ago and one of the reasons he did not attend was that he was also concerned about the difficulty of changing majors in case his declared major was not what he was happy in pursuing. Since you start taking classes immediately related to your major, they do not want students prolonging their time at SLO by constantly changing the minds. If you want a guarantee with your major, go with the schools that gave you the direct admit since SLO will not guarantee you can change.